The San Francisco 49ers needed a win Sunday night.

They got off to a slow start against the Dallas Cowboys, but turned on the jets in the third quarter and held on by the skin of their teeth for a victory that put them at 4-4 heading into their Bye week.

Here are our notes from a wild night where the 49ers looked dreadful in the first half, and looked like a Super Bowl contender for most of the the second half:

First quarter

- Cowboys kick returner KaVontae Turpin is as good of a return man as there is in the NFL. Nice job by the 49ers' coverage team stopping him short of the 30 on the opening kickoff. Patrick Taylor had the tackle.

- Second-and-3 for the Cowboys on their first series -- QB Dak Prescott targets WR CeeDee Lamb who was working on LB De'Vondre Campbell. Campbell continues to be a liability in coverage for the 49ers.

- Third-and-5 for Dallas and LB Fred Warner blows it up. Nice job by the 49ers' defense to stack up a struggling Cowboys run game.

- Deebo Samuel is back and the 49ers immediately toss it to him for no gain. They have to use Samuel differently. Those toss plays just don't hit the way they used to and teams over commit to stopping them.

- The 49ers missed Samuel bad vs. the Chiefs, and they're showing why early. On third-and-6, Purdy found Samuel lined up one-on-one in coverage against a linebacker and hit the receiver for 47 yards. There was some good run after catch from Samuel, too.

- Huh... third-and-10 for the 49ers and Purdy handed it to Jordan Mason for four yards. It set up a 50-yard field goal that Anders Carlson drilled, but the play call was head-scratching. That may be indicative of what head coach Kyle Shanahan thinks of his receiving corps.

- Good tackle in the open field by Campbell on Cowboys TE Jake Ferguson to start Dallas' second drive.

- Ah, there's Dak. He floated one down the left sideline as he got hit by Nick Bosa. The throw fluttered in and allowed Ji'Ayir Brown to run under it for an interception. It looked like rookie CB Renardo Green was also there in coverage.

- Oh dear. Mason is down after a six-yard carry. He jogged off the field and didn't go to the blue tent.

- No running back in the NFL runs into his own linemen more than Isaac Guerendo.

- Purdy is not good throwing out of clean pockets. He badly airmailed a wide open George Kittle on a third-and-6.

Second quarter

- Good tackle in the run game by Charvarius Ward. That was missing from him the first seven games.

- The 49ers can't cover Lamb. San Francisco bit badly on a play-action look on a third-and-short and allowed Lamb to get wide open on a deep crosser.

- Ezekiel Elliott just ran for 11 yards on one carry. That's embarrassing for the 49ers' defense. Elliott has been terrible this season.

- Bosa is on one. He had a sack on a first-and-10 dropback by Prescott, but he's been a menace all night.

- Unreal. Third-and-10 screen and the Cowboys get 10. This drive has been an abomination for the 49ers' defense.

- Now they can't cover something called Luke Schoonmaker, who drew a pass interference in the end zone on Ward. Just terrible.

- Touchdown for Elliott and the Cowboys lead after an 11-play, 65-yard drive. If that's how the rest of this game goes, the 49ers might need to make some significant personnel changes over the Bye week. That was a demolition by a bad Dallas offense.

- 66-yard touchdown to Samuel is negated by a hold on TE Eric Saubert. Doesn't get a lot worse than that. He got worked by a Cowboys DE and had to hang on for dear life and avoid a huge hit on Purdy.

- It looks like Purdy is making a concerted effort to look for easier, shorter throws.

- The 49ers' run game is stuck in mud. Mason is getting no room to run as the 49ers' offensive front is getting moved backward. That unit just hasn't been good enough in the run game.

- Fourth-and-3, the 49ers go for it, the Cowboys bring the house, Purdy finds Samuel wide open and misses badly behind him. That could be a game-swinging play and it's one the 49ers need from their QB and he just flat out missed the throw.

- There's our weekly Nick Bosa penalty. It comes with 6:32 left in the second quarter. This defense isn't good enough for Bosa to give the opposition five free yards.

- Dallas is punking the 49ers. Just the far more physical team through the first 20 minutes.

- Third-and-4, the Cowboys get 28 yards to WR Jalen Tolbert. Prescott had all day to throw and the 49ers did a nice job in coverage, but there just wasn't enough pass rush to ever make him uncomfortable.

- Excellent pass breakup from Malik Mustapha in the back of the end zone. He's coming on nicely in his rookie year.

- No way. Cowboys TE Jake Ferguson just fumbled around four 49ers and he somehow got it back. Just not San Francisco's night in this first half. It's 10-3 after a Dallas field goal.

- Oh, hey Isaac Guerendo. He went for 19 yards, then for 15 yards, then another for 19 that was called back because of a holding call on George Kittle. The 49ers have needed some big plays in the run game, and Guerendo is providing them with Jordan Mason nursing a shoulder injury.

- That holding call was brutal and stopped an excellent 49ers drive. Instead of getting a chance to take shots at the end zone, they got into a first-and-20 and struggled to get moving again. They settled for a 44-yard field goal. Rough.

- Turpin dropped a kickoff, had it bounce right back to him, and he still returned it past his own 30. Unreal bad luck for the 49ers.

- Nice work by San Francisco's defense. Sam Okuayinonu hit Prescott as he was throwing and forced an incompletion on third down. Big spot for the 49ers' offense with all three timeouts and a little less than a minute to get points. They also get the ball back after halftime.

- More bad luck. The Cowboys should've been flagged for kick catch interference and the 49ers should've had 15 free yards. There was no call.

- Vintage Kittle for a pickup of 30 on a short throw. The 49ers have been missing those this year.

- Now Purdy fumbles while trying to pump fake. He has been dreadful in this game. LG Aaron Banks recovered it, but that's a play the 49ers can't have. Now they've used their final timeout and they've lost seven yards.

- Now Purdy badly underthrows Chris Conley on third-and-17 and the 49ers have to punt. Purdy's fumble and inability to complete that pass cost the 49ers a chance at a field goal try before the half. The last six quarters have been a not-so-good referendum on Purdy's ability to lead the 49ers' offense for the next decade.

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Third quarter

- No Mason to start the half. It's Guerendo with the first carry for no gain. Mason has his helmet on the sideline, but that's what he did back in Week 6 when he hurt his shoulder and he never returned to the game.

- Kittle is back. A 43-yard rumble on a shallow crosser. He broke multiple tackles and nearly got the pylon with a dive. The 49ers are in business at the Dallas 4. Now they need to punch it in in the red zone -- an area they've struggled this year.

- That didn't take long. Guerendo plows in for his first-career touchdown and the 49ers are up 13-10. That looked much more like the 49ers' offense we know. They leaned on YAC with their TE, and then got behind their OL to get downhill in the red zone. Really nice work from San Francisco's offense. They needed that.

- Whew. Big hit by Ji'Ayir Brown to stack up a short throw for no gain.

- Sick interception by Deommodore Lenoir. He was one-on-one with Lamb and tried to float a jump ball down the sideline and Lenoir got up to snag it before Lamb could get his hands on it. That's a massive takeaway for the 49ers defense.

- Guerendo has been a little bit of a factor as a pass catcher. He has two catches on three targets.

- Lots of short throws for Samuel. They're almost using those screens as extended run plays. None have broken for big plays yet.

- Good scramble by Purdy on a third down where his WRs were Ronnie Bell, Ricky Pearsall and Chris Conley. It looked like he might've had Guerendo open in the middle of the field, but the smart move on third down was to scramble and get the first down.

- Kittle gets the touchdown to cap another excellent drive by the 49ers' offense. He's up to 101 yards, which gives him 6,750 receiving yards for his career -- tying him with Dwight Clark for third on the 49ers' all-time receiving yards list. That was a sweet throw from Purdy, who slung a sidearm toss over to Kittle on a quick out. Conley cleared the DB with a rub route and Kittle had an easy score.

- Another good defensive stand for the 49ers. Bosa again created some havoc on a third down and forced a tough throw into tight coverage from Ward.

- Nice play by Purdy to pull down a throw on a screen and scramble for 16 yards instead.

- There's Kittle. He picks up 27 and he's up to third place on the 49ers' all-time receiving yards list. It was also his 500th catch as a 49er.

- Guerendo is not very good at making defenders miss in the open field.

- Purdy called his own number on a third-and-goal from the 2 and punched it in. San Francisco is three-for-three in the red zone and they're rolling, up 27-10. They needed this third quarter bad.

Fourth quarter

- Good start to the fourth quarter. On third-and-5 Prescott had nowhere to go thanks to good coverage and Okuayinonu flew in for a drive-ending sack. Not a great pass rush, but it was good enough to get home before coverage could break down.

- Sheesh. What a dreadful decision by Purdy. He turned down a throw on a third-and-1, decided not to run, then tried to throw anyway and the throw got tipped and nearly intercepted for what would've gone for a defensive touchdown. That would have been a disaster that could've swung the game.

- Dallas's offense is cruising after a third-down pass interference by Ward. It looks like the 49ers are happy to let them churn out shorter throws while taking away potential big plays. However, the 49ers are bad at closing games so letting the Cowboys walk down the field is not great.

- And there's a touchdown to Lamb. It's inexcusable for him to be as open as he was. The 49ers have played this year like a poorly-coached team way too often. It's only a 10-point lead with more than half a quarter left. The 49ers are in perilous territory here. How they respond on offense will define a lot of the rest of the year.

- Oh that's fun! A handoff to Pearsall on a jet sweep goes for 39 yards. Dallas was not sitting on that and Pearsall followed a block from Kittle and Conley. Perfect play call and perfect execution from the 49ers offense.

- Sheesh. Purdy on third-and-6 looked indecisive in the pocket again and has to throw the ball away. Samuel is questionable to return with a rib injury so it's not a huge surprise Purdy didn't trust any of his pass catchers in that spot. Carlson drilled a 41-yard field goal. Really nice bounce-back from him after missing a PAT in Week 7.

- Welp. Lamb wide open again. It's a six-point game. This is why falling back into that faux-prevent the previous drive was not a good idea. The 49ers' defense isn't sound enough for that and now Dallas has clawed back into a game they have no business being in. That time it looked like Ji'Ayir Brown got lost.

- Oof. Purdy took a huge sack. Not totally sure how Purdy didn't fumble. Guerendo whiffed a block bad.

- Third-and-10, Purdy checks it down to Kyle Juszczyk well short of the first down marker. Disaster. Absolute, unmitigated disaster.

- On the punt, Conley had a chance to down it at the 22, and inexplicably let it roll to the 25. Unbelievable.

- Warner nearly had an interception on Dallas's first play after the punt. It was an incredible play to knock it down, but he knocked it away from Lenoir, who would've had it for an easy pick.

- Shot play to Turpin, but Lenoir had a hand in there to help force an incompletion. That was a sick throw by Prescott. Terrific coverage by the 49ers' CB.

- WOW. Fourth-and-10 and it looked like there was some pass interference on Brown, but it was just his feet getting tangled with the receiver. Excellent stop by the 49ers' defense when they absolutely needed it.

- Now it's up to the 49ers' offense to just not turn it over.

- They managed to put it away! Whew, the 49ers finally closed out a game after letting go of the rope a little bit.

Final score

49ers 30, Cowboys 24

This article originally appeared on Niners Wire: Notes from 49ers' wild, much-needed win over Cowboys