Jayson Tatum started his night with a turnover and ended it with an air ball. For two quarters between, the Boston Celtics forward looked every bit the superstar he had become on this playoff run, but Tatum and his young teammates have undoubtedly left a championship on the table in Games 4 and 5 of the NBA Finals.

Consecutive fourth-quarter meltdowns will live with these Celtics long after this series if they cannot save their season, and the first team All-NBA face of the franchise will wear the loss, like it or not. This is how the league works, especially since Tatum has been party to a pair of inexplicable late-game disappearing acts.

The latest one turned another five-point lead into a 104-94 loss and a 3-2 deficit in the series on Monday.

"Our backs are against the wall. This is the time that we look at each other in the eyes and we got to figure it out," said Boston's Al Horford. "We have an opportunity. Got to figure it out. There's no tomorrow for us."

The Celtics have one more chance Thursday to avoid becoming a footnote to a Golden State Warriors dynasty, and two if they force a third straight Game 7 against a more veteran team. Tatum has answered the call in three previous elimination games, and he will need to twice more not sport the stink of a title lost.

"You better be confident, right?" said Tatum, who scored 22 of his 27 points in Game 5 through three quarters. "We ain't got to win two in one day. We just got to win one game on Thursday. We've been in this situation before. So it's not over. Got to win on Thursday. That's all we got to worry about right now."

Since taking a 2-1 series advantage against the three-time champions and a 94-90 lead with five minutes remaining in Game 4, Boston's three pillars have wilted with two chances to seize control of this best-of-seven set. For the final five minutes of Game 4 and the first 8 1/2 minutes of the fourth quarter of Game 5, Tatum, Jaylen Brown and Marcus Smart combined to miss 12 of their 13 shots and commit five turnovers.

Golden State outscored Boston in those two highest-pressure stretches of this series, 35-8. The Celtics did not trail the second half of Game 4 but for a minute before being outscored 17-3 in the last five minutes of a 107-97 loss. Boston used a 35-point third quarter in Game 5 to flip a 12-point halftime deficit into a lead as large as five, but a buzzer-beating Jordan Poole 3-pointer gave the Warriors a 75-74 edge entering the fourth quarter, and the Celtics watched that margin balloon to 93-79 over the next 8 minutes, 18 seconds.

During those series-swinging runs totaling 13 1/2 minutes, this is the output of Boston's biggest stars:

• Tatum: 2 PTS (0-4 FG, 0-1 3P, 2-4 FT), 1 AST, 1 TO

• Brown: 3 PTS (1-6 FG, 0-3 3P, 1-2 FT), 0 AST, 3 TO

• Smart: 0 PTS (0-3 FG, 0-2 3P, 0-0 FT), 1AST, 1 TO

Tatum has attempted a team-high 21 field goals in the five fourth quarters of the Finals and made just five of them. Through the first three playoff rounds, Tatum scored 114 points (on 54/49/88 shooting splits) over 17 fourth quarters — bested across the league only by his co-star Brown's 120 points (on 62/67/65 splits).

Their brilliance in crunch time is what has gotten the Celtics this far, and their shortcomings in those same situations during this series are the reason they now face elimination in Game 6 at TD Garden on Thursday. They have both been outplayed by once-forgotten Warriors wing Andrew Wiggins over the last two games.

"All season long it's kind of been like us versus everybody," said Brown, still projecting confidence. "I look at it as no different now. My faith is higher than it's ever been before, so I'm looking forward to Game 6."

Tatum's shooting struggles in this series are especially confounding. Through five games, he is now 19 for 40 from 3-point range (47.5%) and 19 for 82 from inside the arc (23.2%). You would think those numbers would be reversed if his woes were the result of lingering effects from the stinger he initially suffered to his shooting shoulder in Game 3 of the Eastern Conference finals and has aggravated several times since.

Double teams and Wiggins' defensive effort might help explain Tatum's 10 turnovers over the past two games (part of a record 95 turnovers in a single playoff run), but neither is an excuse for missing layups against a team his coach has repeatedly said lacks rim protection. It could be nerves. There is little other reasoning for Tatum's pass to fans in the front row on Boston's first possession of Monday's game.

It could also be exhaustion. Tatum has played a league-leading 943 minutes in the playoffs over 23 games, 67 more than Brown and almost 200 more than Klay Thompson, who leads the Warriors with 751 minutes in 21 appearances. The only perimeter players in history to log so many playoff minutes in a single season with a usage rate as high as Tatum's (29%) are Allen Iverson, LeBron James, Kobe Bryant and Dwyane Wade.

None of them did it following two shortened offseasons in the third year of a global pandemic.

Curry is 10 years Tatum's senior and has had the ball in his hands more in these playoffs. You might think youth serves Tatum, but the Celtics star encounters more contact than Curry offensively and assumes more responsibility on defense. Few, if any, players have ever carried so great a playoff burden at 24 years old.

For what it's worth, Celtics head coach Ime Udoka said fatigue could have been a factor in the fourth quarter of Game 5, because they had expended so much energy coming back from a lackluster start, but he would blame Boston's lack of energy on the 23 games in 58 days. "I don't think that's the reason at all," he said.

Tatum will have to access whatever reserves he has left in his tank Thursday, because there will be no Game 7 if he and the Celtics cannot finish a fourth quarter with the same force they leverage to establish their leads. We have seen Tatum carry Boston in an elimination Game 6 before, when he scored 46 points in a road victory over the defending champion Milwaukee Bucks — the most impressive performance of his young career — but a month and 11 more increasingly pressurized playoff games have passed in between.

"We've been here before, did it against Milwaukee," added Udoka. "Let's bring it back out to the Bay."

Much will be made of Boston's inexperience if Golden State completes this comeback, but Tatum has earned his playoff scars in a pair of Game 7 victories over the previous two rounds, and there is little solace in citing youth as an excuse for a Finals loss. An offseason of debates over his ability to be the primary option on a championship team would await, fair or not, and the sting of defeat will live with him until next he can reach this stage. Ask any number of players outside the pantheon how hard it is to get back here.

Game 6 in the face of elimination against an aging dynasty is truly where legends are made. Curry can add to his, but the two-time league MVP's all-time greatness is certified. Tatum's may lie in this very moment.

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Ben Rohrbach is a staff writer for Yahoo Sports. Have a tip? Email him at rohrbach_ben@yahoo.com or follow him on Twitter! Follow @brohrbach