"I feel very confident that I can throw any pitch that I want to," the Dominican left-hander said through a translator.
Rodriguez (1-0) struck out seven and allowed five hits, his second solid start at home this season. A week ago, he pitched 7 1/3 scoreless innings against St. Louis, but didn't get a decision in the Astros' 5-3 victory.
Last year, Rodriguez had a 2.94 ERA at Minute Maid Park and the Astros won 11 of the 15 games he started here. On the road, Rodriguez had a 6.37 ERA last season, the highest among NL starters.
Even Rodriguez is puzzled by the disparity.
"I don't know what the deal is about being at home," Rodriguez said.
Josh Willingham hit a solo homer in the fourth inning for the Marlins. After that mistake, Rodriguez was virtually untouchable, striking out four of the next seven batters he faced. He retired nine in a row before Cody Ross singled leading off the seventh.
"He was pretty much in command throughout," Houston manager Cecil Cooper said. "He's looking like an ace right now."
"This is a funny game," Willingham said. "Not to say anything against these guys, but we hit Oswalt around and these guys come in and give up only one run in two days. We need to do better at situational hitting, getting back-to-back hits, sacrifice flies and stringing things together."
Florida's Burke Badenhop (0-1), making his first major league start, allowed seven hits with three strikeouts and a walk. The 25-year-old Badenhop came to Florida in the deal that sent Dontrelle Willis and Miguel Cabrera to Detroit.
Marlins manager Fredi Gonzalez liked what he saw from the right-hander.
"I thought he pitched terrific," Gonzalez said. "Unfortunately, Wandy pitched a little better."
Darin Erstad got Houston going with a double to right-center in the second inning. Towles followed with a homer to left, his third of the season, on what Badenhop called "a fat pitch."
Bourn led off the third with a homer to right, his first of the season and second of his career. Bourn is known more for his speed and base-stealing ability, but he knew the ball was gone the instant he hit it.
"I'm not going to hit 40 home runs in a season," Bourn said. "I take them when they come."
Willingham opened the fourth inning with a homer onto the railroad tracks in left field. The Astros had runners on first and third with one out in the bottom of the inning, but Towles grounded into a double play.
Badenhop lasted until the Astros loaded the bases with none out in the sixth. Lance Berkman led off with a walk, Carlos Lee singled and Miguel Tejada beat out an infield hit before Gonzalez brought in left-hander Taylor Tankersley.
"Right there, that was a chance to break the game open," Cooper said.
Rodriguez batted next and grounded out, but he didn't need to help himself with his bat. After Ross singled in the seventh, Rodriguez got the next two Marlins on fly outs, then ended his day by striking out pinch-hitter Robert Andino.
Bourn and Mark Loretta singled off Florida reliever Matt Lindstrom in the Houston seventh. Berkman then doubled off the bullpen fence in left-center to score Bourn and put Houston up 5-1. Berkman has four doubles and seven RBIs in his last six games.
Hanley Ramirez singled in the first inning to extend his hitting streak to 11 games. ... Towles was hit on his left hand by a pitch from Kevin Gregg in the eighth inning. He left the game and was replaced by Brad Ausmus. ... Erstad started for the slumping Hunter Pence, who's hitting .180. Manager Cecil Cooper said Pence needed a day off. "When things aren't going really well for you, you need to clear your head," Cooper said. ... Former president George H.W. Bush and Barbara Bush had front-row seats behind home plate.