San Diego eliminated a 111-win Los Angeles Dodgers squad while Philadelphia ousted defending champion Atlanta and Houston swept Seattle on Saturday in the Major League Baseball playoffs.

Jake Cronenworth's two-run single capped a five-run seventh inning for San Diego as the Padres rallied to beat the Dodgers 5-3 and win their best-of-five National League division series 3-1.

"Since I was a little kid we've been getting beat up by the Dodgers but when it comes down to it and the games matter, this team stepped up top to bottom," hometown Padres star Joe Musgrove said.

"The guys we've got in there, the dogs we've got, when the moment is big these guys turn it on."

The Dodgers went 14-5 during the season against San Diego.

"Disappointment very high. It's crushing," Dodgers manager Dave Roberts said. "We didn't expect to be in this position."

The Dodgers led the MLB in wins this season and won the NL West division by 22 games over the Padres, making it the second-biggest upset in MLB playoff history, eclipsed only when the 1906 Chicago White Sox trailed the Chicago Cubs by 23 games but beat them in the World Series.

"These guys dominated us all year but we got hot at the right time," Musgrove said. "We wanted it for these fans. We wanted it for ourselves. It's a great feeling."

For the first time since 1998, the Padres advanced to the best-of-seven NL Championship Series, where they will face the Philadelphia Phillies, who ripped Atlanta 8-3 to dispatch the Braves in four games.

J.T. Realmuto hit an inside-the-park home run while Brandon Marsh smacked a three-run homer and Bryce Harper added a solo homer for the Phillies, who hadn't reached the playoffs since 2011 or the NLCS since 2010.

"What an opportunity," Harper said. "You've got to beat the champs to be the champs. I get chills, man. We've got two more. We've got (to win) eight more games."

The Braves failed in their bid to become the first MLB repeat champion since the New York Yankees from 1998-2000.

In the American League, the Houston Astros won a marathon contest 1-0 at Seattle on Jeremy Pena's solo home run in the 18th inning to eliminate the Mariners in three games.

Pena's blast after the most scoreless innings in MLB playoff history sent the Astros into their sixth consecutive AL Championship Series.

"I'm tired. That was a long game," Pena said. "But you still got to lock in, try to put together good at-bats. I was just trying to stay inside the baseball. Thought I drove it in the gap, but it just happened to leave the ball field."

The Astros will face either the Yankees or the Cleveland Guardians, who rallied for a dramatic 6-5 victory over New York to grab a 2-1 series lead. Cleveland can advance with a home victory on Sunday.

Cleveland rookie Oscar Gonzalez hit a two-out, two-strike single with the bases loaded in the ninth inning to drive in the two deciding runs.

"I just wanted to put the ball in play. Thank God I got the results," the Dominican said through a translator. "Then I was just waiting for the guys to score and celebrate."

Cleveland trailed 5-3 in the ninth but consecutive singles by Myles Straw, Steven Kwan, Amed Rosario and Jose Ramirez pulled the hosts within 5-4 and loaded the bases, setting the stage for Gonzalez's decider.

At Philadelphia, Realmuto became the first catcher to hit an MLB playoff inside-the-park homer and only the 18th player in all to manage the feat. It was the first such homer in the playoffs since 2017.

At Seattle, relief pitchers were masterful for hours in the first MLB playoff game to go scoreless into the 16th inning. The total of 42 strikeouts in the contest also was an MLB playoff record. (AFP)