LOS ANGELES – Kodai Senga got off to a disappointing start in which there was little mystery about what went wrong: He couldn’t find the record.

David Peterson came in later and pitched in an equally disappointing outing that had few other similarities.

Peterson found the plate, but also found Dodgers barrels, which were hit hard for the first time this postseason.

The Mets’ Plan A failed before the Mets’ Plan B failed to encourage in a 9-0, NLCS Game 1 loss at Dodger Stadium on Sunday night.

Peterson, one of the Mets’ most valuable players through October when he started the postseason with 6 ¹/₃ scoreless innings in relief, looked much deadlier against the Dodgers than against the Brewers and Phillies.

Arguably the Mets’ best bullpen arm allowed three runs (two earned) on four hits and a walk over 2 ¹/₃ innings against arguably the best lineup in baseball.

All the damage against Peterson came in a fourth inning, in which the Dodgers converted four singles, a sacrifice and a Starling Marte error into a three-run frame that blew the game open.

In the inning, Kiké Hernandez lined a single to right and advanced to second base on a bunt by Gavin Lux.

Tommy Edman’s single made it 4-0 before Peterson left a curveball over the heart of the plate to Shohei Ohtani, which is not recommended.

Ohtani fired it off the bat and into right-center of the wall at 116.5 mph.

Marte dropped the carom off the wall, which mattered when Edman slid in safely just before the relay throw.

After Mookie Betts grounded out – even the out was knocked off his bat at 100 mph (163.6 km/h) – Freddie Freeman sent a single into left field, and Brandon Nimmo’s home throw was too late to make a sliding to capture Ohtani.

Peterson settled in from there, but only pitched through the fifth inning in a 40-pitch outing, meaning he won’t be available for Monday’s game and likely won’t be stretched out enough for a long start in Game 5, either. if the Mets decide to pivot away from Senga.

After a late start to his season following offseason hip surgery, Peterson was reliable and excellent for the Mets during the regular season, pitching to a 2.90 ERA in 21 starts.

A prized left arm for a team without many lefties in the bullpen and bullpen experience, he was taken out of the rotation in October for Sean Manaea, Luis Severino, Jose Quintana and a stretched Senga.

In the immediate aftermath of Sunday’s defeat, the question was whether Peterson would remain relegated or whether he would jump Senga into the starting group.