David Peterson stymies Nationals to keep Mets’ playoff hopes alive

WASHINGTON — David Peterson’s season is concluding just as it has reached a zenith.

The rookie pitcher didn’t even possess a roster spot when summer camp began, but became an integral piece of the Mets’ rotation out of necessity. Now the Mets have to love the potential gem they have unearthed.

Thursday night Peterson kept the Mets’ scant playoff hopes alive with his strongest start of the season in a 3-2 victory over the Nationals.

The Mets (26-31) are still mathematically alive for second place in the NL East, which carries a postseason berth, and also breathing, albeit barely, in the wild-card race. Their deficit on the Giants and Phillies for the final wild-card spot is two games with three remaining. The Brewers also sit ahead of the Mets. In the race for second place in the NL East, the Marlins began play Thursday night with a 2½-game lead on the Mets with the Phillies sitting in between.

Peterson (6-2) lasted seven innings — his longest career start — and allowed one earned run on four hits with one walk and four strikeouts. The left-hander lowered his ERA to 3.44, an oasis for a team whose back-end rotation options — Rick Porcello, Michael Wacha and Steven Matz — have all disappointed at various degrees.

Peterson was strong late into his start, escaping trouble in the sixth by retiring Kurt Suzuki and Yan Gomes in succession after Juan Soto had doubled with one out. In the seventh he allowed a leadoff single to Josh Harrison before getting three outs.

It was a second straight superb start for Peterson, who allowed only one run over six innings in a victory over the Braves last Saturday. The left-hander also reached double digits in strikeouts for the first time in his career with 10 in that game.

Robinson Chirinos, who entered batting .149, delivered his first homer of the season, a two-run shot in the fifth, that gave the Mets a 2-1 lead. Guillermo Heredia singled leading off the inning against Patrick Corbin before Chirinos cleared the fence in right-center.

In the sixth, Chirinos hit a grounder to the first-base hole — and beat Corbin to the bag — for an RBI single that extended the Mets’ lead to 3-1. Robinson Cano’s bunt single against the shift started the rally before Amed Rosario walked and Heredia’s fly ball to right advanced Cano to third.

Harrison’s RBI single in the fourth brought in the game’s first run. Soto walked leading off the inning to begin that rally.