Rapid Reaction: Mets 8, Nationals 5

WASHINGTON -- Well, maybe the New York Mets won't need much of Matt Harvey down the stretch.

David Wright delivered a clutch RBI single in the seventh and Yoenis Cespedes produced three extra-base hits as the Mets beat the Washington Nationals, 8-5, in Monday's series opener at Nationals Park.

The Mets (76-61) opened a five-game lead over the Nationals (71-66) for first place in the National League East.

The Mets' magic number dipped to 21.

Wright broke a 5-all tie with a run-scoring single against Casey Janssen in the seventh. Daniel Murphy followed with a sacrifice fly and Cespedes had an RBI double later in the frame against Matt Thornton.

Cespedes doubled twice and homered in the victory.

The relief trio of Erik Goeddel, Dario Alvarez and Hansel Robles combined to retire all 10 batters they faced leading into Jeurys Familia for the ninth. Familia converted his 37th save in his first appearance in a week.

Not Niese: In a start manager Terry Collins labeled the biggest of Jonathon Niese's career, the southpaw flopped. Niese surrendered a grand slam to Wilson Ramos and an RBI double to Jayson Werth and was knocked out with one out in the fourth with the Mets trailing, 5-3. Niese also had surrendered five-run frames in each of his previous two starts, both in third innings against the Philadelphia Phillies. He has a 10.53 ERA over his past four starts.

Michael Conforto, Kelly Johnson and Cespedes had produced solo homers against Max Scherzer as the Mets built a 3-0 lead.

Niese barked at plate umpire Paul Nauert about the strike zone after getting removed from the game.

Ouch: Carlos Torres, who entered once Niese was knocked out, pulled up lame after scooping up a grounder near the first-base line in the fifth and was forced to depart. Torres was diagnosed with a strained left calf. That's when Goeddel took over and the young bullpen arms dominated.

Welcome back: Alvarez fell behind in the count with three straight balls, but rallied to strike out Bryce Harper for the final out of the sixth. The faceoff marked the only six pitches Alvarez has thrown in the majors this season.

What's next: Harvey gets to further chip away at his innings allotment when he takes center stage at Nationals Park on Tuesday. Harvey (12-7, 2.60 ERA), who may not pitch for a while afterward to conserve innings, opposes right-hander Jordan Zimmermann (12-8, 3.38) on Tuesday at 7:05 p.m. ET.