WASHINGTON -- Bryce Harper homered, Ian Desmond had three extra-base hits, Danny Espinosa provided his first two RBIs of the season, and the Washington Nationals beat the White Sox 5-2 Wednesday night to stay unbeaten at home.
In a game that began 16 minutes late because, the Nationals explained, the umpires got stuck in traffic, Washington starter Jordan Zimmermann (2-0) limited Chicago to two runs and seven hits in seven innings. Both runs scored on groundouts.
Drew Storen pitched the eighth, and closer Rafael Soriano worked around a hit in the ninth for his fourth save in five chances.
Harper hit his fourth homer into the second deck leading off the fourth against Gavin Floyd (0-2), who allowed five runs and nine hits in 5 1-3 innings.
Desmond tripled, doubled twice and scored twice as reigning NL East Washington improved to 5-0 at Nationals Park.
Every Nationals starting position player reached base at least once; the only one without a hit, Kurt Suzuki, walked three times.
After Chicago drew within 3-2 on Alex Rios' RBI groundout in the top of the sixth, Washington chased Floyd in the bottom half by tacking on two more runs.
Desmond led off with a triple, Espinosa followed with an RBI double, Suzuki walked and Zimmermann sacrificed the runners over.
Floyd was done, and lefty reliever Donnie Veal came in to face Span but gave up a run-scoring single and was replaced by righty Nate Jones. With runners on the corners, Jones got Jayson Werth to ground into a 5-4-3 double play.
Harper turned on Floyd's first pitch of the fourth, an 86 mph offering that never stood a chance. With a "thwack!" off the bat, the ball arced into the second deck beyond right field, and Harper paused for a moment to watch his shot before sprinting around the bases.
That gave the Nationals 11 homers in their last four games, 15 for the season. The 14 entering Wednesday were a franchise record through a season's first seven games.
Floyd struck out the next two batters, but then got into more trouble, giving up Desmond's double and Espinosa's single that gave Washington a 2-1 lead.
Harper's next time at the plate, in the fifth, he followed a single by Werth with a single up the middle of his own, this time on a 91 mph first pitch. TV replays showed Harper's bat split on impact with the ball, then broke completely as the wood slapped against his back on his follow-through.
Ryan Zimmerman followed with an RBI single to shallow right.
NOTES: Zimmermann is 7-0 in his last 13 starts at home; his most recent Nationals Park loss came last season on May 17 against Pittsburgh. ... Rios' four-game homer streak ended. ... A smattering of applause from the crowd of 24,586 greeted the first announcement of Adam Dunn's presence in the White Sox lineup. He played in Washington in 2009 and 2010. Usually Chicago's DH, he sat out Tuesday's series opener and played left field Wednesday, going 0 for 4 with an RBI groundout in the sixth. ... Chicago 2B Gordon Beckham sat out after hurting his left wrist Tuesday. He's not sure how long he'll be sidelined. Jeff Kepplinger started at second Wednesday, with Conor Gillaspie at third. ... White Sox pitching coach Don Cooper is still hospitalized with a stomach illness.
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