HOUSTON -- Game-winning homers are becoming routine for the Houston Astros.

Hunter Pence hit a solo shot off Jose Mesa on the first pitch of the 13th inning and the Astros took advantage of a questionable umpire's call to beat the Philadelphia Phillies 5-4 on Tuesday night.

The rookie center fielder's drive was the third walk-off homer for the Astros in six days. Carlos Lee and Mark Loretta ended games with homers against Colorado last Thursday and Friday.

"If you keep expecting to beat the other team's closer, that's not going to happen very often," said Craig Biggio, who went 2-for-5 with an RBI single. "But you take it whenever you get it."

Pence hammered the first pitch from Mesa (0-1) off the left-field facade. He sprinted around the bases as fireworks exploded. The excitable 24-year-old is hitting .563 with two homers in his last three games.

"My swing feels good, but I wouldn't say I'm locked in," said Pence, leading all rookies with a .345 average. "I'm just going up there, trying to put a good swing on the ball."

The game probably should've never come to that.

The Phillies took a 4-3 lead to the ninth, but the Astros loaded the bases with one out against closer Antonio Alfonseca.

Lee hit a grounder to shortstop Jimmy Rollins, who flipped to Chase Utley to start a potential game-ending double play.

The relay throw appeared to get Lee by half a step, but first-base umpire Lance Barksdale called Lee safe and Biggio scored to tie the game. Biggio started the rally with a single.

Phillies manager Charlie Manuel ran out to protest, to no avail.

"Alfonseca pitched really well," Manuel said. "He did a good job, he got the double play ball and we executed. And the umpire missed it. He told me, 'I got it right.' What I told him was, 'You missed the call. You blew it."'

Loretta grounded out to force extra innings, but the Phillies were steamed about having to keep playing.

"It's frustrating," said right fielder Shane Victorino. "That's all I have to say. Just look at the replay. I'm not going to say what I saw."

Matt Albers (2-4) shut out the Phillies in the 12th and 13th and the Astros scored on a bases-loaded walk for the second straight night, winning for the eighth time in their last nine home games.

Houston starter Roy Oswalt gave up 10 hits and struck out six. He had won his last five starts against Philadelphia and still hasn't lost to the Phillies since May 9, 2003.

Ryan Howard hit a two-run double and Houston native Michael Bourn knocked in the go-ahead run in the seventh inning with his first career double for the Phillies, who have dropped six of their last eight.

Wes Helms had an RBI double in the second inning, but the Astros answered with three runs in their half.

Loretta and Mike Lamb led off with consecutive singles and Luke Scott walked to load the bases. The Phillies' bullpen walked in two runs in Monday's 7-5 loss and starter Adam Eaton did it again on Tuesday, missing low with a 3-2 pitch to Brad Ausmus.

Oswalt grounded into a double play, but Lamb scored to put Houston up 2-1. Biggio then singled to left, scoring Scott.

Rollins and Bourn singled in the third before Howard doubled off the right-field wall to tie the game again. Howard has 36 RBI since coming off the disabled list on May 25.

Both starters stiffened after that -- Eaton struck out five of the next eight batters he faced, while Oswalt retired nine in a row after Howard's hit.

Helms led off the seventh with a line-drive double into the left-field corner. Ausmus then fielded Rod Barajas' bunt and threw out Helms at third. Two batters later, Bourn doubled over Scott's head in right field to score Barajas and make it 4-3.

Eaton allowed four hits in six innings and matched a season-high with seven strikeouts. Ryan Madson relieved and Morgan Ensberg, pinch-hitting for Oswalt, led off the seventh with a single to center.

Three batters later, Lee singled to right but Ensberg was thrown out at the plate by Shane Victorino. The Phillies lead the majors with 30 outfield assists.

Trever Miller relieved Oswalt for the eighth and Howard drove a towering fly ball to straightaway center. Pence caught it at the top of Tal's Hill, one step from the 436-foot mark on the wall, next to a flagpole that's in play.

"I've never seen a ball hit that far," Pence marveled. "That just shows the kind of strength that he has. That's an area no man really touches."

Biggio and Pence singled off Alfonseca with one out in the ninth. Lance Berkman walked for the third time before Lee stepped to the plate.

Notes

• Biggio's first single was his 3,008th career hit, breaking a tie with Al Kaline for 25th all-time.
• Pence, a rookie, has hit safely in 29 of his last 37 games.
• Oswalt gave up at least eight hits for the fourth straight start.
• Cole Hamels, Wednesday's scheduled starter for Philadelphia, pinch-hit in the 11th and flew out.
• Jamie Moyer, Monday's losing pitcher, pinch-hit for the first time in his career in the 13th inning.