Nationals 8, Mets 2 (10): Rookie Bryce Harper hit a two-run homer and drove in the go-ahead run with a single in the 10th inning to lift visiting Washington to its third straight win.
Michael Morse clubbed a two-run homer after Ryan Zimmerman delivered a three-run double in the six-run 10th as the Nationals extended their lead atop the National League East to 4 1/2 games over the Atlanta Braves.
Tom Gorzelanny (3-2) pitched 1 2/3 innings for the victory while Tim Byrdak (2-2) absorbed the loss after facing only two batters. Pedro Beato gave up the hits to Harper, Zimmerman and Morse.
A costly error by Mets shortstop Ruben Tejada on a potential double-play ball opened the door for Washington's 10th-inning outburst.
David Wright and Ike Davis hit solo homers - the 15th for each player - for the Mets, who tumbled to their fourth consecutive defeat and 10th loss in 11 games.
Nationals starter Jordan Zimmermann allowed one run on four hits through six innings but was removed for a pinch hitter despite throwing only 89 pitches.
Mets right-hander Chris Young gave up two runs on three hits in seven innings, not allowing a hit after the first inning and retiring 18 of 19 at one point.
Harper staked Zimmermann to a 2-0 first-inning lead with his ninth homer, a towering blast to right that ended a 20-game homerless drought.
Wright cut the deficit in half in the fourth inning with a two-out shot and Davis tied it in the seventh with a line drive off the right-field foul pole against Mike Gonzalez, who allowed his first homer in more than 13 months.
GAME NOTEBOOK: The Mets tied a franchise record for the most runs allowed in any extra inning. ... Zimmerman was named the NL player of the week Monday. He batted .500 (15-for-30) with five home runs and nine RBIs last week. ... Wright has hit five of his 15 homers in eight games against Washington. ... Zimmermann has pitched at least six innings in all 20 starts this years. ... Nationals SS Danny Espinosa extended his hitting streak to nine games with a first-inning single. ... Mets SS Tejada (3-for-4) has hit safely in five straight games and 11 of 12. ... Washington placed SS Ian Desmond on the 15-day disabled list due to a tear in his left oblique and called up OF Corey Brown from Triple-A Syracuse.