PHILADELPHIA — Maybe Jacob deGrom simply benefited from 10 days of rest. It would make sense that a breather would help, especially after a season spent emptying the tank deep into October.

Whatever the reason, the one-man wrecking crew who descended upon Citizens Bank Park on Sunday was a sight to behold. DeGrom pitched a one-hitter in the Mets’ 5-0 victory over the Phillies, recording the first complete game and shutout of his major-league career.

“It was a lot of fun,” said deGrom, who fanned Odubel Herrera to cap his masterpiece. “I definitely wanted a strikeout there too. Definitely fun. Hopefully I have many more.”

In becoming the first Mets pitcher to toss a shutout since Bartolo Colon last September, deGrom struck out seven, walked one and needed 105 pitches to finish off the 39th one-hitter in club history. It was the first for the Mets since R.A. Dickey’s in 2012.

The only hit was a two-out single by pitcher Zach Eflin in the third inning. The Phillies didn’t have another baserunner until Ryan Howard’s leadoff walk in the eighth, and he was wiped out on a double play.

advertisement | advertise on newsday

In his last four starts, deGrom has a 0.93 ERA, a 0.76 WHIP and 27 strikeouts in 29 innings. “It’s awesome,” catcher Rene Rivera said. “He was on today. He mixed his pitches well. We had a game plan and we stuck with it. It’s easier when you’ve got a guy where all four pitches were working.”

DeGrom also singled with two outs in the fifth and scored from first on Jose Reyes’ double to the gap in left-center, gobbling up ground with long strides like a long-haired gazelle. He also took away a bunt hit from Cody Asche, bounding off the mound to field the ball cleanly before making an accurate throw while falling away from his target.

Then, of course, there was his pitching. With a fastball that hummed in the mid-90s and an arsenal of breaking pitches that he commanded at will, he pitched to one more than the minimum number of Phillies.

“There was all that concern about his velocity and everything else early,” Terry Collins said, a reference to a first half in which deGrom constantly battled without his best stuff. “But he’s just gotten a little stronger, and a little stronger, and as he showed, the rest did him good.”

Yoenis Cespedes played for the first time since July 8. Starting in leftfield in his return from a strained right quadriceps, he went 0-for-3 with a walk.

Mets videos

Curtis Granderson hit his 16th homer, a blast that landed in the bullpen in right-center with two outs in the third. Asdrubal Cabrera hit his 13th homer, a two-out, two-run shot in the eighth. And Juan Lagares, starting his third straight game against a righthanded pitcher, had a two-out RBI triple in the second.

DeGrom was hitless in his last 18 at-bats before his single, but it was on the mound where he asserted his dominance.

“I was hoping that I’d have one like this, where you go out there, you feel like everything’s working,” said deGrom (6-4, 2.38 ERA). “But it’s part of the game. You don’t always feel good when you go out there, so you’ve got to find a way. Today I was fortunate enough to feel good and keep them off of the scoreboard.”

Collins said deGrom’s two-seamer looked better than it had all season and that his command finally caught up with his increased velocity. Perhaps it was the fruits of the 10 days of rest.

“Just getting a break,” deGrom said. “You go out there every five days and it’s a lot of throwing.”