SAN DIEGO -- Call it a walk, a base on balls or a free pass -- the terminology doesn't really matter.

The Astros were able to take advantage of their chances to stroll down to first base after ball four was called on Thursday night.

Four of a season-high nine walks drawn by the Astros came around to score, including two in the 10th inning, which helped lift Houston to a 6-3 victory over the Padres in front of a crowd of 18,618 at PETCO Park.

"To be able to put good at-bat after good at-bat -- that's what we were able to do, and that was sure nice to see," said Astros manager Brad Mills. "It's something that we've noticed and we've kind of been striving to get to. It was nice to see those good at-bats come in such a crucial part of the game."

No two free passes were more important than the back-to-back, two-out walks drawn in the 10th inning by Humberto Quintero and Oswaldo Navarro off Padres reliever Luke Gregerson, who hadn't walked two batters in one inning all season.

After Gregerson (2-3) retired the first two batters of the inning, Quintero reached first when a 3-1 fastball from Gregerson could not trim the outside corner. Navarro then joined Quintero on the basepaths when a 3-2 slider was called inside.

That set the table for Michael Bourn, who delivered the tiebreaking hit for the Astros (32-48) when he sent a 2-2 slider into right-center field for a triple to bring home pinch-runner Jason Castro and Navarro and make the score 5-3.

Bourn then scored on a single to right by Jeff Keppinger, giving the Astros an insurance run before Matt Lindstrom retired the side in order in the bottom of the frame to earn his 19th save of the season.

"[The Padres'] bullpen has been great this year, and the guys were having great at-bats," Astros outfielder Jason Michaels said. "We were able to get on base, and [Bourn] had the big hit there. That's a huge hit."

Walks and patience at the plate were also the driving forces behind Houston's second inning, in which they tagged Padres starter Jon Garland for three runs. After Michaels led off the inning with a home run to left, Garland walked the bases loaded with two outs before Keppinger lined a two-run single to right field that scored Geoff Blum and Chris Johnson and extended Houston's lead to 3-0.

"I lost the zone," said Garland, who walked six batters total and threw 115 pitches in five innings. "I threw too many pitches early in the game. I wasn't throwing the ball, I was pushing it up there and searching for it. Walks killed me."

That looked like it would be enough run support for Astros starter Brian Moehler, who allowed one run in 5 2/3 innings, to earn his second consecutive win. But the Padres (46-33) rallied to tie the game in the seventh off of reliever Wilton Lopez on a sacrifice fly by Oscar Salazar to score Nick Hundley, who tripled to start the inning, and a single to center by David Eckstein to bring home Tony Gywnn.

"I threw the ball in and out tonight," Moehler said. "I feel like location was pretty good, and we made some defensive plays when we needed them."

Moehler got a no-decision, but earned praise from his manager.

"What a great job he did," Mills said. "He put us in a position to win a ballgame again, and you can't say enough about what he did."