After Houston blew the lead in the ninth inning, Bill Spiers' RBI single with one out lifted the Astros to a wild 5-4 win over the Padres on Thursday, tying their first-round playoff series 1-all.

The Astros took a 4-2 lead into the ninth thanks to the B's -- Jeff Bagwell, Craig Biggio and Derek Bell -- but Billy Wagner allowed a two-out, two-run homer to pinch-hitter Jim Leyritz.

Then in the bottom half, Dan Miceli gave up Ricky Gutierrez's infield single to shortstop leading off. Brad Ausmus sacrificed, Trevor Hofffman relieved, and Gutierrez stole third base uncontested. Spiers followed with a single to right on a 1-2 count.

"We thought if we could just hold 'em, the game was still tied and we could get the game-winning run," Spiers said.

Wagner, who got the win, was shaky down the stretch, blowing consecutive save chances against the Mets last month by allowing homers to Brian McRae and Mike Piazza.

"Billy has done a heck of a job all year," Spiers said. "You have to give a lot of credit to Leyritz. ... He battled and fought off some good pitches and was able to get a pitch to hit for a home run."

Wagner threw eight straight fastballs to Leyritz, including a 98 mph pitch that Leyritz sent over the right-field fence.

Wagner, who converted 30 of 35 save opportunities in the regular season, allowed Ken Caminiti's single with one out in the ninth ahead of Leyritz's clutch postseason homer.

While with the New York Yankees in 1996, Leyritz hit a dramatic three-run, eighth-inning homer against Atlanta's Mark Wohlers to tie Game 4 of the World Series at 6. The Yankees went on to win in 10 innings and defeated the Braves in six games.

The previous year, his 15th-inning home run off Tim Belcher won Game 2 of the Yankees' first-round series against Seattle.

It was the Astros' 28th victory in their last at-bat. It was also the seventh one-run game the teams have played this year, including San Diego's 2-1 victory in the series opener Tuesday.

"It takes an awful lot of pressure off," Houston manager Larry Dierker added.

The series shifts to San Diego's Qualcomm Stadium for games Saturday night and Sunday. Left-handers Mike Hampton (11-7) of Houston and Sterling Hitchcock (9-7) are scheduled to start Game 3.

The Astros had taken control of the game thanks to the Killer B's, who finally lived up to their nickname.

Bagwell drove in Houston's first three runs and Biggio scored twice. Bell rifled a 3-1 pitch from former Astros reliever Donne Wall into the left-field seats for a leadoff homer in the eighth and a 4-2 lead.

The B's went 0-for-10 in Tuesday's 2-1 loss after going just 2-for-37 in a sweep by Atlanta in last year's division series. Of course, all the Astros were frustrated Tuesday when Kevin Brown struck out 16, the second-most ever in the postseason.

On Thursday, they combined to go 3-for-11 with four RBIs and three runs scored. Bell snapped a 0-for-21 postseason slump.

The Astros snapped a six-game playoff losing streak dating to the 1986 NL championship series against the Mets.

Padres starter Andy Ashby lasted just four innings, the fifth time in his last seven starts that he's gone five innings or less. He allowed three runs and six hits, struck out four and walked one.

Astros starter Shane Reynolds allowed two runs and four hits in seven innings.

Biggio singled leading off the first, took third on Spiers' double to left and scored on Bagwell's groundout.

Biggio walked leading off the second, just ahead of the inning's key play. Spiers lifted a fly ball to center field and Steve Finley tried to make a sliding catch, but the ball bounced just in front of him and skipped away for a double, moving Biggio to third. Bagwell singled to center with one out to score Biggio and Spiers.

The Padres got two runs with no outs in the sixth. Quilvio Veras hit a leadoff single and scored when Finley doubled off the manual scoreboard on the left field wall.

Tony Gwynn singled in Finley, but Reynolds jammed Ken Caminiti for a weak comebacker to start a double play, then struck out Greg Vaughn.

San Diego right-hander Joey Hamilton, who had been in the running to start Game 3, threw three scoreless innings in relief of of Ashby.

Notes: Padres officials expect a sellout crowd of between 64,000 and 65,000 Saturday night, making it the largest crowd ever to see a baseball game in San Diego. ... Reynolds didn't walk a batter in his final three starts, but walked Veras leading off the game. ... Until Brown's performance on Tuesday, no Padres pitcher had struck out more than six batters in a postseason game. ... The Padres started their opening day lineup for just the 31st time in 164 games. .... Biggio, a four-time Gold Glove winner, also made a nice play to end the fourth inning, ranging to his left and diving to stop Wally Joyner's grounder, throwing him out. In the second, second baseman Veras gloved Reynolds' two-hopper scooped the ball to shortstop Chris Gomez to start an inning-ending double play.