WASHINGTON (AP) — Carlos Lee hit a two-run homer, rookie Hunter Pence added a tiebreaking solo shot, and Roy Oswalt made his first relief appearance in more than a year, helping the Houston Astros edge the Washington Nationals 4-2 Tuesday night.

Brad Lidge, newly reinstalled as Houston’s closer, pitched the ninth inning for his first save since Sept. 28, 2006, and the Astros ended a seven-game road losing slide.

All but one of the game’s runs came on homers, with Washington’s Ronnie Belliard connecting off Chris Sampson (7-6) in the first inning and Ryan Zimmerman doing the same in the fourth.

Sampson went 6 2-3 innings, allowing those two runs and six hits, for his first victory since June 8. He was pulled after hitting Brian Schneider on the back of the right arm with a pitch and replaced by NL All-Star Oswalt, who’s 8-6 with a 3.91 ERA in 21 starts this season as the Astros’ ace.

But because Houston is off Thursday — and is short a reliever with Chad Qualls starting a three-game suspension — Oswalt entered in the middle of a game on what would be his normal side-session day.

The right-hander last pitched in relief on July 8, 2006, against St. Louis. He threw three pitches to pinch-hitter Robert Fick, who flied out to right on the third offering to end the inning.

Oswalt was lifted for a pinch-hitter in the top of the eighth, and Dan Wheeler came on to pitch the bottom half. He was followed by Lidge, who had been 0-for-3 in save opportunities this season and came off the disabled list last week.

The game was tied at 2-2 heading into the fifth thanks to Lee’s drive to left off Tim Redding (1-2) in the third.