Houston ? Roy Oswalt stumbled and fell in the middle of the field. Then he got up, reached back and put the Houston Astros in control of their first-round playoff series.

Not bad for a No. 3 starter.

Oswalt pitched into the eighth inning, striking out seven of the next 12 batters after his awkward spill, and the Astros beat the Atlanta Braves, 7-3, Saturday night to take a 2-1 lead in their best-of-five series.

Houston can advance to its second consecutive NL championship series with a victory today at home. Brandon Backe will pitch for the Astros against Game 1 loser Tim Hudson, coming back on three days’ rest.

Mike Lamb hit a tiebreaking homer in the third for the Astros, who after seven first-round exits from the playoffs are trying to eliminate the Braves in the division series for the second year in a row.

Craig Biggio, the 39-year-old second baseman who has spent his entire career in Houston and last week agreed to a contract for 2006, hit three doubles and scored twice. Morgan Ensberg, who had five RBIs during a 10-5 victory in the series opener, added a pair of RBI doubles to the delight of a boisterous home crowd.

“Last year, we got to really see what our crowds were all about in this building,” Biggio said. “They’re your 10th guy.”

Oswalt already had wasted a two-run lead when he fell on the mound in the middle of his windup for an 0-2 pitch to Marcus Giles in the third.

Houston's Roy Oswalt delivers against Atlanta. Oswalt pitched into the eighth inning of the Astros' 7-3 victory over the Braves on Saturday night in Houston.

“My back foot slipped off the back of the rubber, and once my feet gave way, I started to throw the pitch anyway, and my mind said, change real quick, don’t lob one up there and let the guy hit it out,” Oswalt said. “I went ahead and took that one on the chin.”

After getting up and shaking his head, Oswalt threw a 96 mph fastball that Giles swung at and missed.

That was Oswalt’s first strikeout, and it got him back on track after a strange sequence in the second inning when the Braves tied the game.

“He’s a tough cookie,” Atlanta manager Bobby Cox said.

Losing pitcher Jorge Sosa, a reliever-turned-starter, gave up three runs and seven hits over six innings in his first postseason appearance. After joining the Braves’ rotation in mid-June, he went 7-0 in 12 road starts.

By the time Oswalt left to a loud standing ovation with one out in the eighth and Giles on first, Houston led 7-2. Andruw Jones then hit an RBI double off reliever Dan Wheeler, but that was all the Braves got. Brad Lidge closed it out in the ninth.

The teams had about 14 hours to rest for Game 4, which will be at 12:09 p.m. today.

Atlanta has won 14 straight division titles but hasn’t made it past the first round of the playoffs since 2001.

The Braves will turn to Hudson in the hopes of sending the series back to Atlanta for a deciding game Monday night.