HOUSTON (Ticker) -- It may have taken 161 games, but the Houston Astros now control their own destiny.

Craig Biggio and Jeff Kent both homered twice and Roy Oswalt tossed seven effective innings as the Astros inched closer to a postseason berth with a 9-3 triumph over the Colorado Rockies .

With their 17th straight home victory, Houston moved within one victory or one loss by the San Francisco Giants of clinching the National League wild card. The Astros can secure their fifth playoff berth in nine years with a win Sunday at home, where they have not lost since August 23.

"While winning tonight is fun and watching the scoreboard was fun ... our job's not done," Houston interim manager Phil Garner said. "We've got to work to do. Tomorrow is a big game. It could very well be the biggest game we play all year. We control our destiny. We win tomorrow, we've got this thing. It's not like we have to depend on someone else to do something. It is in our hands."

And getting the ball for the Astros will be Roger Clemens , who could lock up his seventh Cy Young Award with a solid performance. The 42-year-old righthander will be going on three days' rest.

"We want to throw the best guy we can out there," Garner said. "It's going to be tough for him. When he pitches, he gives us everything he's got. If he can give us a few innings, then everybody else is going to have to pitch in." Starting just as the Giants lost to the Los Angeles Dodgers , Houston put itself in position to advance to the postseason by homering in six of the first seven innings.

Kent's two homers, a solo shot in the second and a two-run blast in the fifth, gave him 278 as a second baseman - breaking Ryne Sandberg 's record.

"When I am old and gray and my kids ask me how good I was, I might be able to relish it, but right now I'm more focussed on getting back to where I was a couple of years ago (the World Series)," Kent said.

Biggio had solo shots in the first and third inning as Houston torched Colorado starter Shawn Estes (15-8).

"Today was a great day, but we still have a game of baseball to play tomorrow," Biggio said. "We've been to the postseason four times when I've been here, and I think in three of them, it came down to the last day. We don't do anything easy around here."

The early offense made things easy on Oswalt (20-10), who was spectacular with the lead. The righthander became the National League's first 20-game winner by allowing a run and five hits in seven innings. He did not walk a batter and struck out six in winning for the seventh time in eight decisions.

With his fourth victory in as many lifetime decisions against the Rockies, Oswalt ran his career record in Houston to 33-12. He is 11-4 at Minute Maid Park in 2004.

"It's great to do it, especially in a playoff atmosphere," Oswalt said of winning 20. "If you do it and you're out of the playoffs, it doesn't mean as much. It's always hard to set win goals at the start of the season, but this is just one-third of the goals I set for myself. We want to get the playoffs and then get to the World Series."

Estes was hammered for five runs and seven hits in four innings. He surrendered four of the Astros' six home runs.

"They hit good pitches," Estes said. "I have never seen a team on a roll like they are right now. They are hot, there is nothing else I can say. I wouldn't change any pitch that I threw."

"He didn't have his best stuff, but was willing to battle and go back out there," Colorado manager Clint Hurdle said. "We had to go out and get some runs. I'm sure it's not the way he wanted to end this season, but it does not take away from everything he has accomplished."

After Biggio opened the bottom of the first inning with his 23rd homer, Vinny Castilla countered with his 35th in the top of the second. But Kent hit his 26th in the Houston half of the second and Biggio homered in the third.

Eric Bruntlett homered in the fourth, Kent hit another in the fifth for a 7-1 lead and Morgan Ensberg hit his 10th in the seventh.

Kent and Biggio have three multi-homer games this season.