SAN DIEGO — The Mets needed Mad Max, but got the sad version instead Sunday.

Resembling the pitcher who underwhelmed for so much of the first half, Max Scherzer gave the Mets one last pre-All-Star-break clunker, while the lineup behind him started its vacation a day early.

It translated into a 6-2 loss to the Padres at Petco Park that siphoned any momentum the Mets hoped to carry into the break.

Their season’s best six-game winning streak that ended Saturday a distant memory, the Mets lost the series and fell to six games below .500.

Francisco Alvarez and Francisco Lindor carried the team to a three-game sweep in Arizona to begin the road trip, but the Mets need other contributors.

None emerged over the last two games, in which the Mets combined to score only three runs.

Scherzer reached the All-Star break with a 4.31 ERA after allowing five earned runs on six hits with seven strikeouts and three walks.

Manny Machado’s two home runs accounted for all of the damage against Scherzer, who has allowed 18 homers in his 16 starts this season.

Scherzer fell into an immediate hole on Machado’s three-run homer in the first inning on a high slider.

It marked a seventh straight start in which Scherzer allowed a homer — he surrendered three solo blasts in his start Tuesday in Arizona.

On this day Ha-Seong Kim singled leading off the game and Fernando Tatis Jr. delivered a double with one out before Machado unloaded to left field.

With the blast the Mets have now been outscored 65-26 in the first inning this season.

The Mets received consecutive singles from Jeff McNeil and D.J. Stewart in the second inning off Joe Musgrove before Alvarez hit into an inning-ending double play.

In the fourth the Mets loaded the bases when Pete Alonso and McNeil were hit by pitches in succession after Francisco Lindor singled.

But all three runners were left stranded as Musgrove struck out Stewart and Alvarez to end the inning.

Machado returned to torment Scherzer in the fifth with a two-run homer to right that extended the Padres’ lead to 5-0.

The homer, which followed a Tatis single, was Machado’s third in the series.

Mark Canha was plunked leading off the sixth — the fourth hit batter of the game by Musgrove — before Lindor struck out and Alonso hit into the Mets’ third double play of the game.

Canha’s two-run double in the eighth got the Mets on the scoreboard. Luis Guillorme doubled leading off and Nimmo walked before Canha — who entered the game in the first inning to replace Tommy Pham (groin) — delivered.