(Photo credit: John Jones-Imagn Images)

Brandon Nimmo hit a walk-off RBI single to send the host New York Mets over the Philadelphia Phillies by a score of 6-5 in a back-and-forth battle between the top two teams in the National League East on Tuesday night.

The Mets squandered a 5-2 lead before producing the winning rally without allowing Jhoan Duran (6-6) to record an out in the ninth. Starling Marte, Pete Alonso and Brett Baty all singled before Nimmo delivered his fifth career walk-off hit.

Mets closer Edwin Diaz (6-2) retired all five batters he faced, four by strikeout, after entering a 5-5 game.

The Mets, who entered the day with a 2 1/2-game lead over the Cincinnati Reds in the race for the final NL wild card berth, stretched it to 3 1/2 after the Reds' 6-3 loss to the Dodgers in Los Angeles later in the night. New York has won four of five after opening August 5-13. The Mets are five games behind the NL East-leading Phillies, who have lost three of five.

The teams were locked in a scoreless duel until a chaotic fifth, when Bryce Harper hit a two-run single for the Phillies before the Mets sent 10 batters to the plate while scoring five runs in the bottom half. Juan Soto had an RBI single and Pete Alonso ripped a go-ahead two-run double before Mark Vientos added a run-scoring single and Nimmo chipped in a sacrifice fly.

The Phillies began their comeback in the sixth when Edmundo Sosa had an RBI single against Huascar Brazoban. The struggling Ryan Helsley gave up the lead in the eighth when he walked Nick Castellanos with one out and allowed a two-run homer to ex-Mets outfielder Harrison Bader.

Helsley has suffered four blown saves and has a 10.38 ERA in just 11 appearances for the Mets, who acquired him from the St. Louis Cardinals on July 30.

Mets starter Sean Manaea allowed two runs on six hits and no walks while striking out eight over 4 2/3 innings.

The Phillies' Jesus Luzardo gave up four runs on five hits and three walks while striking out five over four innings.

--Field Level Media