TJ Rivera is the newest unlikely contributor to the Mets’ playoff push.
The rookie infielder hit a go-ahead homer in the 10th and drove in three runs to help New York salvage a 4-3 win over Washington on Tuesday night at Nationals Park.
Rivera homered off Mark Melancon on an 0-2 pitch shortly after Jeurys Familia blew a two-run lead in the ninth.
Noah Syndergaard had been in line for a win with seven innings of one-run ball. The Mets (77-68) go for their seventh straight series win Wednesday afternoon.
“Did I look like I’d done it before?” Rivera said after smashing his first major league homer, a 10th-inning solo blast that led the Mets’ victory.
“That was good. I was trying to keep my cool.”
New York was just three outs away from a 3-1 win when the Nationals rallied against Familia, largely due to a throwing error by Jose Reyes. His miscue put runners on second and third with no outs, and both runners would score to send the game to extra innings.
Rivera started at second base as manager Terry Collins continues to mix and match there. He went 2-for-3 with two RBIs before his game-winning hit. Rivera hammered a cutter into the seats in left, the first of his career.
Jerry Blevins struck out Daniel Murphy to end the game with the former Met representing the winning run.
New York suffered its first blowout loss in almost three weeks Monday when they fell 8-1 to the Nationals, and though Tuesday wasn’t a must-win, it represented an important game. A potential sweep would have halted the team’s momentum, and the Mets can’t afford to lose games that Syndergaard starts.
Syndergaard suffered a loss the last time out against the Nationals, also matched up against AJ Cole, but he was dominant Tuesday. He allowed four hits, struck out 10 and walked one.
Washington took an early lead when a leadoff walk and a stolen base led to a run, but Syndergaard made quality pitches afterward to hold Washington to 1-for-9 with runners in scoring position. Still, the Nationals grabbed the lead after Bryce Harper walked and stole second before scoring on Wilson Ramos’ RBI double.
Stolen bases have plagued Syndergaard all season long and also burned him in his last outing against Washington. He allowed four in that Sept. 2 game and they played a factor in the two runs he yielded in the 4-1 loss at Citi Field.
The Nationals were 9-for-10 in stolen-base attempts against him entering Tuesday, Syndergaard would strand a runner in scoring position in that early inning Tuesday, then settled in. A leadoff double in the fifth in a 3-1 game put Syndergaard in a bind, but he struck out the next three batters. He worked around a one-out double in the sixth by Murphy with a strikeout and a fly-out.
He now has struck out double-digit batters in 10 career games and recorded his 200th career strikeout when he fanned Danny Espinosa in the fifth.
The Mets gave Syndergaard only one run of support the last time he faced the Nationals, but they solved Cole this time. They applied pressure all night by putting a runner on in all five of his innings, and cracked him in the third and fifth.
Two runners were left on in the first and second innings, but Rivera got the Mets on the board with a two-out RBI single in the third
Two innings later, New York caught a break when Curtis Granderson hit what should have been a double-play grounder to Ryan Zimmerman, but the ball went under Zimmerman’s glove and resulted in an RBI triple into the right-field corner. Rivera added a sacrifice fly to boost the lead to two runs.
The Mets could have added more, but finished just 1-for-8 with runners in scoring position through the first five. They stranded eight in that stretch.

RESULTS
NY Yankees 3 LA Dodgers 0
NY Mets 4 Washington 3 (10 innings)
Pittsburgh 5 Philadelphia 3
Tampa Bay 6 Toronto 2
Minnesota 8 Detroit 1
Baltimore 6 Boston 3
Miami 7 Atlanta 5
Cincinnati 6 Milwaukee 4
Oakland 5 Kansas City 4
White Sox 8 Cleveland 1
Texas 3 Houston 2
St. Louis 4 Chicago Cubs 2
Arizona 11 Colorado 4
Seattle 8 LA Angels 0
San Diego 6 San Francisco 4