HOUSTON -- Dontrelle Willis gave Florida the NL wild-card lead with an outstanding all-around effort.
"He's a complete guy," Florida manager Jack McKeon said. "He hits, he fields, he pitches. With him in the lineup, it's like an extra bat."
McKeon was asked if there is anything Willis can't do.
"He probably is going to have to work on covering second base," McKeon said with a smile. "He's a gamer. He's a competitor. You almost expect him to go out and have a game like this every time. It's a surprise if it doesn't happen."
Florida moved a half-game ahead of the Astros in the wild-card standings, taking the top spot for the first time since after games of Aug. 30.
Willis (21-8) tied St. Louis ace Chris Carpenter for the major-league lead in victories and complete games by winning his sixth straight start. He allowed eight hits, struck out four and walked one in the opener of a key four-game series.
Willis connected for a two-run shot off Scott Strickland in the sixth inning, giving the Marlins a 6-1 lead. It was his third career homer and first since April 14, 2004, against Montreal in Puerto Rico. He also scored twice and has 11 RBI this year. He hasn't lost since Aug. 12 against San Francisco.
The pitcher's batting average of .259 is higher than his ERA of 2.49.
"He's doing something amazing out there this year," teammate Juan Pierre said. "He's playing both sides of the plate and you don't see that very often. Winning 21 games and hitting the way he is is unreal.
"He's a position player in a pitcher's body."
Willis still isn't satisfied.
"I continue to hurt my team with my bunting," he said. "I'm definitely going to work on that in the offseason.
"But I play hard. I definitely leave it all on the field every time. (Team management) is still upset at me for diving headfirst back to the base. But that's the only way I know to play."
Carlos Delgado, Miguel Cabrera and Jeff Conine also homered for Florida, which won for the fifth time in seven games. The Astros have lost three of four and are a half-game ahead of Philadelphia for second place in the wild-card chase.
"We just had a lot of Dontrelle Willis tonight, more than I'd care to see," Houston manager Phil Garner said. "Brandon (Backe) threw the ball well. He had a lot of good pitches and only a few mistakes. That was a decent job against a team that is really swinging the bat well."
"What worries me is that we've had three games that are stinkers. We didn't look good against Milwaukee and we didn't look good tonight. They pretty much took it to us tonight."
Backe (8-8) lasted five innings and allowed four runs, three earned, and seven hits in his second game back after missing five weeks with a ribcage injury.
"He was on a roll," Backe said about Willis. "I looked up and he had only 39 pitches going into the fifth inning. That means he had a lot of easy outs and a lot of easy innings.
"He doesn't have 21 wins for nothing. He has very good stuff. He mixes up his pitches well and he's difficult to hit. He's a good hitter as well."
Lance Berkman was 0-for-3 against Willis.
"He's not a guy who's going to give you a lot of different looks," Berkman said. "When you go up there, you know pretty much what you're going to get. He's got something goofy on that fastball. You just can't seem to get a good hit on it."
Delgado hit a two-run homer in the first, and the Marlins stretched their lead to 3-0 with an unearned run in the fourth.
After Damion Easley walked, Pierre had a bunt single and third baseman Jose Vizcaino was charged with an error on the throw, allowing Easley to reach third. Paul Lo Duca then drove in Easley with a single.
Cabrera led off the fifth with his 31st home run to make it 4-0. Jason Lane hit his 22nd homer leading off the bottom half.
After Willis homered in the sixth, Berkman's sacrifice fly in the bottom half made it 6-2.
Conine added a two-run shot in the ninth off Russ Springer.
- The 23-year-old Willis is the first pitcher younger than 24 to win 20 games since Ramon Martinez in 1990 -- and the youngest lefty since Vida Blue in 1971, according to the Elias Sports Bureau.
- Lo Duca was back in the lineup after missing two games with a hamstring injury that has bothered him since Aug. 15. He has missed nine games with the injury.
- Houston's Brad Ausmus leads NL catchers with 54 hits since July 1.
- Astros 3B Morgan Ensberg missed his sixth game with a bruised wrist. He is day-to-day.
- Willis is the first pitcher with 20 wins and 20 hits since Houston's Mike Hampton in 1999, according to the Marlins.