WASHINGTON -- The Washington Nationals got their offense going as soon as the rain finally dissipated.
Adam Dunn's grand slam capped a five-run second inning after a rain delay of more than three hours and the Nationals beat the San Diego Padres 13-1 Saturday night for their most lopsided victory of the season.
"Going through a delay like that, it's always better to come out and give yourself some breathing room right away," said Ryan Zimmerman, who homered and drove in three runs. "Hopefully we can continue that kind of play. We knew it was going to rain for a little while, but after that it was clear."
Dunn finished with five RBIs and Nyjer Morgan equaled a career high with four hits for Washington, which snapped a two-game losing streak. The 13 runs are the most the Nationals have scored at home since moving to D.C. before the 2005 season.
"It was a good, clean ballgame for us," Washington manager Jim Riggleman said.
After San Diego stranded a pair of runners in the second, the game was halted for 3 hours, 11 minutes by a line of storms that drenched Washington, threatening the Nationals' 2-0 lead. It was the 17th Nationals game delayed by rain this season, with those stoppages totaling 33 hours, 42 minutes.
Padres starter Tim Stauffer (0-2) threw 17 pitches in the first inning before the deluge forced him from the game.
"When they called it, it looked dark but it hadn't started raining. I was a little bit shocked and obviously disappointed not to get another crack at it," Stauffer said. "Certain things you can control and certain things you can't, and that's one of those things."
Once play resumed at 10:40 p.m. EDT, manager Bud Black called on Luis Perdomo, who struck out two before allowing five runs in a rally ignited by Nationals starting pitcher J.D. Martin, who batted for himself to save Washington a pinch hitter.
Martin fouled off four two-strike pitches before completing a 10-pitch at-bat with a walk on a 3-2 pitch, moved to third on Morgan's single up the middle and scored when Cristian Guzman beat out an infield single to short. Zimmerman walked to load the bases before Dunn crushed Perdomo's first-pitch fastball over the center-field wall for his 25th homer and second grand slam of the season.
Tyler Clippard (1-0) relieved Martin and fanned a career-high seven in four innings in which he allowed one hit.
"Everybody did their job tonight," Clippard said. "That's one of the best games we've played all year."
Everth Cabrera had three hits for San Diego, which has dropped six of seven.
Padres first baseman Adrian Gonzalez played in his 305th consecutive game, tying the franchise mark set by Steve Garvey. Gonzalez's streak, which dates to Aug. 15, 2007, is the longest active streak in the majors.
Washington took a 2-0 lead in the first on Zimmerman's 17th homer, a shot to center.
In the sixth, Zimmerman had an RBI double, Dunn collected hit a sacrifice fly and Josh Willingham had a run-scoring single.
Kevin Kouzmanoff ruined the shutout with an eighth-inning RBI single off Joe Beimel. Nick Johnson drove in two with a bases-loaded single in the bottom of the inning and Willie Harris plated another on a fielder's choice.
Martin was removed before the third inning. He allowed two hits and a walk in two scoreless innings, while Stauffer gave up two runs on three hits in an inning. ... Perdomo hadn't allowed a run in 8 2/3 innings over six appearances since June 26, and has been scored upon in 11 of his 22 outings. He struck out a career-high seven in three innings. ... Clippard's seven strikeouts established a single-game record for Nationals relievers. ... The game drew a crowd of 21,834, but less than 3,000 hung around after the lengthy stoppage. One of the hearty holdovers was WWE wrestler Dave Batista, a Washington, D.C., native. ... The teams combined for 23 strikeouts, with Nationals hitters fanning 15 times.