Gonzalez allowed three singles and two walks. He allowed one baserunner to get as far as second, and struck out five hitters. He retired his last 10 batters and is 2-0 with a 0.75 ERA.
Miami entered an NL-best 5-2, a year after finishing with a league-high 100 losses. Led by Giancarlo Stanton, the Marlins were averaging a majors-best six runs a game, but they couldn't solve Gonzalez or four relievers.
Stanton went 1 for 4 with a single; it was his first game in 2014 without an RBI. Miami put runners on second and third with two outs in the seventh against Drew Storen, but pinch-hitter Greg Dobbs flied out.
Gonzalez, who was born in Hialeah, Fla., has won his last four starts against the Marlins. His 3-0 mark against them in 2013 was part of an overall 14-5 edge the Nationals held in the teams' series a year ago.
On Tuesday, the Nationals took a 1-0 lead in the first, when Jayson Werth hit a two-out double to left-center and LaRoche followed with an RBI single.
With two outs in the sixth, LaRoche was at first and Bryce Harper at third after both singled, and a pitch momentarily got away from catcher Jarrod Saltalamacchia. LaRoche took off, and Saltalamacchia's throw was dropped by second baseman Jeff Baker, who was charged with an error. LaRoche was safe, and Harper scored without a throw, making it 2-0. Rendon then tacked on a run-scoring single, before adding a two-run double off Mike Dunn in the eighth.
Rendon, usually Washington's second baseman, started at third because Ryan Zimmerman is dealing with a sore throwing shoulder.
NOTES: The announced attendance was 21,728, about half of capacity. ... Zimmerman hasn't played in the field since Saturday but said he hopes to be back at his usual spot against Miami on Wednesday. He is making adjustments, including changing his throwing motion and practicing less to ease up on wear and tear. ... Five of Miami's eight position players in the starting lineup Tuesday were signed as free agents in the offseason. ... Washington reconfigured its rotation slightly for the rest of the Marlins series and the three-game set at Atlanta that follows. RHP Jordan Zimmermann will start Wednesday, facing Miami RHP Jacob Turner, and RHP Stephen Strasburg goes Thursday against RHP Tom Koehler. Then, for the Braves series that starts Friday, it will be RHP Tanner Roark, RHP Taylor Jordan, and Gonzalez. ... The Marlins were 26-55 on the road last season, 12-26 at NL East opponents. ... Miami has the third-youngest roster in the majors, and is one of only three teams without a rookie.
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