Wild-card series down, Division Series here we come. MLB's 12-team postseason bracket has already been whittled down to eight contenders. Now, the top two seeds from each league are set to join the fray. After advancing directly to their ALDS and NLDS slots via byes, the Astros, Yankees, Dodgers and Braves will take on challengers.

That means aces on the mound. The day begins with Max Fried for the Braves, continues with AL Cy Young favorite Justin Verlander taking the hill in Houston and Gerrit Cole starting for the Yankees, and concludes with NL ERA leader Julio Urias getting the ball for the Dodgers. Their opponents, fresh off hard-fought wild-card wins, will be using No. 3 starters and hoping to get the ball rolling toward upset victories.

All four series started Tuesday in a busy day of baseball.

Dodgers jump to early lead, hang on vs. Padres

Baseball's best team didn't look rusty after all. The 111-win Dodgers raced out to a five-run lead against the division rival Padres and kept the challengers at bay to take NLDS Game 1, 5-3.

Trea Turner started the scoring with a first-inning homer for Los Angeles, and the rest of the lineup piled on in the third. NL ERA champ Julio Urias started and allowed three runs across five innings to get the win. Relief ace Evan Phillips escaped the stickiest situation by inducing a double play off the bat of Wil Myers in the sixth inning, when the Padres had the tying run on base.

Game 2 will set up a matchup of the Padres' Yu Darvish and Dodgers legend Clayton Kershaw.

Yankees ride Gerrit Cole to Game 1 win vs. Guardians

The Guardians struck first, but Gerrit Cole and the Yankees got the last laugh in ALDS Game 1. The Yankees ace gave up an early homer, but then settled in to strike out eight over 6 1/3 otherwise scoreless innings.

New York got a homer from Harrison Bader to tie the game shortly after Cleveland's Steven Kwan opened the scoring. In an odd fifth inning where Josh Donaldson got thrown out during confusion over a near-homer, Jose Trevino eventually gave the Yankees the lead with a sacrifice fly. Anthony Rizzo's huge homer eventually sealed a 4-1 win for the Bronx Bombers.

In the end, it was an ace-like performance from Cole on a day where other top seeds saw their frontline starters struggle following long layoffs. Aaron Boone will get to hand the ball to Nestor Cortes Jr. — who posted a team-leading 2.44 ERA in the regular season — for Game 2.

Yordan Alvarez obliterates walk-off homer to crush dream Mariners game

For 26 outs of ALDS Game 1, the legend of Julio Rodriguez and the drought-busting young Mariners looked stronger than the legend of Justin Verlander. But it was not stronger than the legend of Yordan Alvarez.

The mammoth slugger crushed a walk-off three-run homer with two outs in the ninth inning, sending the Houston crowd into delirium and stunning the Mariners.

The day had begun with the young Mariners jumping all over AL Cy Young favorite Justin Verlander. Led by Rodriguez — who tallied two extra-base hits and three runs — the Mariners poured 10 hits and six runs on Verlander in four innings. But the Astros chipped away at it. Yuli Gurriel and Alex Bregman homered to bring the Astros within two in the later innings.

Then, in the ninth inning, Mariners reliever Paul Sewald hit David Hensley and gave up a single to Jeremy Pena. With Alvarez, who already had two RBIs on the day, coming up, Mariners manager Scott Servais turned to lefty starter Robbie Ray to get the final out. It did not work.

Alvarez, whose .306/.406/.613 line made him the second-best hitter in baseball behind Aaron Judge this year, fouled off one fastball and then sent the next one into orbit.

Seattle's fortunes couldn't have turned much more precipitously. With a win, they could have secured a 1-0 lead with a road win and sent dominant ace Luis Castillo to the mound in Game 2 with the chance to take a commanding series lead. Instead, the Astros will thunder ahead favored to make their sixth consecutive ALCS.

Phillies keep the line moving, hold on for Game 1 win vs. Braves

Do you like rallies? You might like the Phillies. After just scraping into the postseason, the Phillies have won three straight — first sweeping the St. Louis Cardinals and now taking Game 1 of the NLDS against the 101-win Atlanta Braves. Tuesday's series-changing victory came thanks to a parade of hits.

Nick Castellanos led the way with 3 hits and 3 RBIs as the Phillies knocked Atlanta ace Max Fried from the game early, then held on tight. Ranger Suarez started for the Phillies, allowing 1 run in 3 1/3 innings, then handed it off to a Phillies bullpen that used six pitchers to finish it off. Newly appointed closer Zach Eflin held on to give Philly the win despite a furious Braves comeback attempt in the ninth inning.

You can follow all the action right here on Yahoo Sports.

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