Robinson benched first baseman Nick Johnson, catcher Brian Schneider and outfielder Brandon Watson in favor of Matthew LeCroy, Wiki Gonzalez and Marlon Byrd, respectively. Robinson wanted a more right-handed lineup against Pettitte.
Robinson also dropped Jose Vidro from the second hole in the batting order to third and pushed up Royce Clayton from the bottom of the order to the second hole.
It didn't work out, as the Astros defeated the Nationals, 7-3, in front of 31,662 at Minute Maid Park.
The Nationals got off to a good start against Pettitte in the first inning when Byrd led off with a home run on an 0-2 pitch, but fielding miscues by shortstop Clayton, starter Ryan Drese and left fielder Alfonso Soriano in the third inning led to three unearned Astros runs, eventually making Drese the losing pitcher in his 2006 debut.
Astros shortstop Adam Everett led off the inning by hitting a slow roller to Clayton, who grabbed the ball and threw it over the head of LeCroy at first base, and that allowed Everett to advance to second base.
"It was one of those do-or-die plays. Unfortunately, it got away. [Best case scenario], I was hoping the ball would stay on the field so Everett could stay at first, but things seemed to escalate from there."
Pettitte was the next hitter and -- on a hit-and-run play -- singled to right field on the drawn-in infield to tie the score at 1.
After Biggio popped up, Taveras hit a grounder up the middle that Drese purposely blocked with his right foot. The ball then ricocheted toward the shortstop area, but it went past Clayton for a base hit, which allowed Pettitte to go to third base.
"If you look at the replay, Royce would have gotten there. If I could take it back, I would. It's kind of a reaction," Drese said.
After Lance Berkman struck out, Morgan Ensberg doubled near the left-field line. Pettitte scored easily and Taveras scored all the way from first base after the ball went under Soriano's glove for an error.
In the fourth, shortstop Adam Everett had an RBI groundout to give the Astros a 4-1 lead off Drese, who lasted four innings and gave up four runs -- one earned. Drese threw 85 pitches and 48 went for strikes. It was his first regular-season appearance since having surgery to repair a cartilage tear in his right shoulder last September.
"I thought I threw the ball pretty well -- all things considered. They didn't hit the ball too hard, but they executed," Drese said. "I just threw too many pitches today. ... I was a little bit wild at times, but I'm staying downhill with my delivery."
Drese's outing, however, wasn't enough to give the bullpen a rest. The relievers pitched another four innings and gave up three runs. With the bullpen overworked, Robinson would like Monday's starter, John Patterson, to go deep in the game.
Asked how much the team needs a well-pitched ballgame, Robinson said, "As bad as a barefoot man needs a soft shoe. ... We need Patterson to go deep into the game tomorrow."
Nationals reliever Joey Eischen was on the mound when the Astros scored the two more runs on the bottom of the fifth inning. With the bases loaded, Everett drove in two more runs with a single to center field.
Eischen has now given up five runs in 2 2/3 innings this season. He plans to arrive early at Minute Maid Park on Monday, look at video tapes and see what he his doing wrong on the mound.
"I want my confidence," Eischen said. "I want to pitch, play and not think and, right now, I'm thinking too much. I'm trying to be too smart. I'm trying to be a cute pitcher. I'm not a cute guy. I'm a groaner."
The Nationals made it a 6-3 game in the top of the sixth inning off Pettitte, when Soriano hit a two-run homer.
"He's dangerous. You've got to expand the zone, and I didn't do that," Pettitte said about his former teammate. "It was extremely frustrating at-bat for me, looking back on the game. When that happened, I threw him a fastball in, and he pulled it foul. I went right back in there, and it was in, and he's a good hitter. He hit it out. That was frustrating."
The Nationals had Pettitte on the ropes throughout the game. In the second inning, Soriano led off with a double. After LeCroy grounded out, Soriano stole third. But after Ryan Zimmerman grounded out to the Pettitte, Berkman threw out Sorinao, who was leaning too far from third base for the final out of the inning.
In the seventh inning, Pettitte left the game with the Nationals having runners on first and second with one out. Reliever Trevor Miller entered the game and induced Vidro to lineout into a double play.
Asked why they couldn't capitalize on Pettitte, Clayton said, "He's a veteran pitcher and he has a great catcher [in Brad Ausmus] behind him. When you have two veteran guys like that, then you are not going to make too many mistakes -- as far as what they are going to do. They are not going to pitch you the same way. I think he varied up his looks and got you out. Your first at-bat you got cutters, and then he went to his changeup. We hit some balls hard, just kind of in the wrong part of the ballpark."
Washington also had scoring opportunities against relievers Dan Wheeler and Brad Lidge. In the eighth inning, with Wheeler on the mound, the Nationals had runners on first and third with two outs.
Robinson had the option of using Daryle Ward or Marlon Anderson as pinch-hitter, but the skipper opted to go with Schneider, who was in a 2-for-17 slump. He hit a deep fly ball to right-center field with Taveras catching the ball for the final out of the inning.
"I was really close on that pitch. I thought I had a good pitch. I had a pretty good swing on it. It's just a matter of inches. I'm not going to say I could have hit it a mile," Schneider said. "The ball got in on me just a tad bit. If I got the head out a little bit more, I would have hit it hard somewhere."
Ward did enter the game in the ninth inning and hit a leadoff double, but he was left stranded as Lidge struck out the side.
"We had a lot of chances, period. We just couldn't get a hit except for the two home runs we got," Robinson said. "But we're giving away too many runs early in the ballgame."
Bill Ladson is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.