Nationals 5, Mets 2: Adam LaRoche belted a two-run homer to back the stellar pitching of Gio Gonzalez as visiting Washington beat skidding New York for its fourth straight win.

Gonzalez (13-5) allowed one run on two hits in seven innings to outduel knuckleballer R.A. Dickey, who had his winning streak snapped at 11 games in losing for the first time in more than three months.

Red-hot Ryan Zimmerman had three hits to extend his hitting streak to eight games and help send the Mets to their fifth consecutive defeat and 11th loss in 12 games.

Dickey (13-2), who was bidding to become the first 14-game winner in the majors, gave up five runs on eight hits in six innings to absorb his first loss since April 18.

LaRoche swatted his 17th homer, a towering shot into the upper deck in right field, to spark a four-run sixth inning. Jesus Flores also had an RBI single in the inning, with all the runs coming with two outs.

Danny Espinosa went 2-for-4 with an RBI double to run his hitting streak to 10 games and Tyler Clippard earned his 17th save for the Nationals, who maintained a 4 1/2-game lead over Atlanta atop the NL East Division.

Jordany Valdespin homered for the Mets, who took their first lead in 42 innings on the current six-game homestand on Ronny Cedeno's second-inning single.

GAME NOTEBOOK: Gonzalez tied Dickey for the most wins in the NL. ... Dickey's 11-game winning streak was the third-longest in team history, behind Tom Seaver (16) and Dwight Gooden (14). ... Zimmerman, the reigning NL Player of the Week, has 13 multi-hit games in his last 27. He is batting .485 (16-for-33) with four homers and 10 RBIs during his eight-game tear. ... Valdespin set a franchise record with his fifth pinch-hit homer of the season for the Mets, who are 1-10 since the All-Star break - their worst record to start the second half since going 1-14 in 1962. ... Espinosa entered Tuesday's game with one hit in 17 career at-bats against Dickey. ... Mets SS Ruben Tejada sat out after he was spiked in the leg in Monday's game. ... New York called up right-handed reliever Manny Acosta from Triple-A Buffalo and demoted RF Lucas Duda.