HOUSTON(AP) Adam Dunn bristled when asked about his baserunning mistake after the Washington Nationals ' 13-2 win over the Houston Astros on Saturday.

And why not? He and the Nationals don't get many chances to celebrate victories like this.

''Hey, we won and that was a lot of fun,'' Dunn said. ''Lot of hits, lot of runs. Next?''

Nick Johnson , Josh Willingham and Dunn homered in consecutive at-bats and the Nationals set season highs for hits and runs. Washington had three straight shots for the first time since the franchise relocated from Montreal in 2005 and the 21 hits were the most since the move.

The Nationals reached 13 runs for the first time since a 13-5 win over the Chicago Cubs on Aug. 22, 2008.

But the way Washington's season has gone, manager Manny Acta wasn't ready to exhale until about the eighth inning.

''This is not hockey or basketball,'' he said. ''There's no 24-second clock and every comeback has been done in baseball. Not until you get to the eighth inning and you're up by, let's say, 10 runs, do you try to feel a little bit comfortable.''

The run support helped rookie starter Craig Stammen relax long before that.

Stammen (2-4) gave up nine hits in his first complete game and Washington's fourth this season. He threw only 107 pitches, taking more chances with Houston's hitters because of the lopsided score.

''The game's not on the line, so each pitch isn't make-or-break,'' Stammen said. ''It actually makes you make better pitches.''

Willingham added a two-run homer and an RBI double and Alberto Gonzalez had a pair of RBI singles for the Nationals.

Houston starter Mike Hampton (5-6) gave up nine hits in 3 2-3 innings, his shortest outing of the season. He pored over a video replay of his performance and didn't think he pitched that poorly.

''I thought I must've thrown a lot of balls up in the zone,'' Hampton said. ''That just wasn't the case. Sometimes, you've just got to tip your hat to the other team.''

The Nationals joined the New York Yankees as the only teams to homer in three straight at-bats this season. Nick Swisher , Robinson Cano and Melky Cabrera homered in consecutive at-bats against Baltimore at Yankee Stadium on May 20.

Hampton had won three of his last five starts, but the Nationals jumped on him from the first inning.

Nyjer Morgan led off with a single and scored on Willingham's two-out double. Willingham scored on Dunn's single, just the second time in six outings that Hampton had allowed more than one run.

Dunn came home on Josh Bard 's double, but Astros shortstop Miguel Tejada told Hampton that Dunn didn't step on second base. Hampton threw to Tejada to appeal and second-base umpire Jim Wolf called Dunn out.

A mistake like that might've cost the Nationals in most games, the way their season has gone. But the offensive outburst made it a footnote.

''Obviously, we should've had one more run,'' Dunn said. ''But we've had chances to break open games a bunch and tonight, we finally did it.''

Michael Bourn scored runs in the first and third innings to tie it, but the Nationals opened the fourth inning with three straight singles to retake the lead.

Morgan drove in a run with a sacrifice fly and Cristian Guzman tacked on an RBI single to put the Nationals ahead 5-2.

Paulino relieved and gave up a bases-loaded single to Ronnie Belliard in the fifth.

In the sixth, Paulino struck out Guzman before Johnson drove a 2-2 pitch into the right-field seats, just out of the reach of Hunter Pence . Willingham homered to left on Paulino's next pitch, and Dunn worked a 3-2 count before hitting his homer.

''Tough night at the ballyard,'' said Houston manager Cecil Cooper . ''We got a lot of pitches up and they didn't miss many.''

Gonzalez and Stammen started the seventh inning with back-to-back doubles off Jeff Fulchino to make it 10-2. Johnson drove in Stammen with a single before Willingham hit a home run to left for his third multihomer game this season.

NOTES: Bourn stole a career-high three bases to raise his NL-leading total to 32. ... Willingham has a 10-game hitting streak. ... Nationals 3B Ryan Zimmerman rejoined the team after attending his grandmother's funeral in North Carolina early Saturday.