CINCINNATI -- Sure, Edinson Volquez already had four starts for the Reds this season. But Wednesday marked the overdue debut of the Volquez everyone had been waiting for.

In the type of start that made him a 17-game winner and first-time All-Star a season ago, Volquez silenced the Astros for a 3-0 win. Over his career-high eight scoreless innings, only one hit was allowed with just one walk and one hit batter.

"He threw a masterful game," Reds manager Dusty Baker said.

This was an important win for the Reds, who were trying to avoid being swept in three games by Houston. It also gave Cincinnati an 11-10 record to finish April.

In the first inning, Miguel Tejada's two-out double to right field was nearly a home run but skipped off the wall for the lone Houston hit. In the third inning, J.R. Towles was hit by a pitch to start the inning. After that, Volquez retired 17 in a row until pinch-hitter Jason Michaels drew a two-out walk in the eighth.

A strikeout pitcher prone to running his pitch counts into the stratosphere, Volquez struck out six batters and used just 106 pitches. Normally one to throw 95-97 mph, he took a little off his fastball and threw more often in the 92-93-mph range. It helped him notch the best outing of his career.

"I was thinking last night about this game and how I would pitch," Volquez said. "Me and [catcher] Ramon [Hernandez] did a good job. I was aggressive in the zone and attacked the hitter."

While that sounds basic enough, the outcome was a huge 180-degree turnaround from Volquez's previous outing on Friday vs. the Braves. In that 4-3 loss, Volquez lasted just five innings, and although he also allowed only one hit, he walked a career-high seven. That included five walks in the 40-pitch fourth inning alone.

"Hopefully he's back on track," Baker said. "He was still trying to find it, and he found it today -- big time. He was pitching, throwing strikes and therefore kept his pitch count down. His strikeouts were down, but they put the ball in play."

Volquez entered the night 2-2 with a 6.20 ERA in the previous four outings. He now owns a 4.45 ERA.

"Some guys have great starts [to the season], but it didn't happen for me," Volquez said. "I had four OK games. Tonight I was good. I threw a lot of strikes."

The Astros, who snapped an eight-game winning streak at Great American Ball Park going back to last season, think Volquez can pitch better than he did.

"I didn't think he was on the top of his game," Michael Bourn said. "I think he was OK. He left some balls over the plate for us. Some people made some good swings. I didn't make any good swings, but on a regular [day], we'll get to him. He has good stuff, no doubt. But I'm not going to say he was at his best."

Volquez and Astros starter Felipe Paulino (0-2) exchanged zeros over the first four innings until the Reds got on the scoreboard in the fifth. Laynce Nix led off with a triple down the right-field line and into the corner. With the infield drawn in, freshly recalled Adam Rosales bounced an RBI single up the middle for a 1-0 Reds lead.

Rosales, who came up when third baseman Edwin Encarnacion went on the disabled list Tuesday, pumped his fist after he reached first base.

"That's a situation you were born and raised to do," Rosales said. "That's your job to get him in. That's what was going through my mind -- get him in. When I got to two strikes, I had to change my approach a little bit. I wasn't going to drive it, but I put some good wood on it."

After Joey Votto led off the Reds' sixth with a routine fly to left-center that became a single as center fielder Bourn bumped into big left fielder Carlos Lee and the ball bounced off Lee's glove for a two-base error charged to Bourn. Votto scored from third base on Nix's infield RBI single to the hole between short and third.

Rosales' sacrifice fly in the eighth provided ample cushion for Volquez, who did have the tying run at the plate after Michaels' walk. Pinch-hitter Lance Berkman roped a tough line drive to right field that Jay Bruce snared with a diving catch.

Volquez was lifted for a pinch-hitter in the bottom of the eighth and did not get a chance to complete the game. Francisco Cordero notched three straight outs for his seventh save.

"No chance. I was done," said Volquez when asked if he wanted to hit in the eighth. "My mind was out. Dusty told me when I tried to go to the clubhouse to wait. I could go back if we got some more runs, but my mind was out [of the game]. I wanted to see Cordero close the game."