HOUSTON -- Bronson Arroyo was beginning to feel cursed.
There were the four unearned runs on a fielding error in one game and the blown save in another. In all, the Cincinnati pitcher had four quality starts but remained winless a month into the season.
It was the Reds' largest winning margin and Houston's ninth loss in the last 10 games.
In his sixth start, Arroyo (1-2) retired the first nine batters before walking Craig Biggio to start the fourth. Mike Lamb singled and Biggio scored on a sacrifice fly by Luke Scott later in the inning.
"It's been a little drought for me," he said. "If I can just keep going out and giving us quality starts, I knew eventually I'm going to have to win a game."
Arroyo walked Lance Berkman to start the sixth and retired the next six batters before being replaced by John Coutlangus in the eighth.
Arroyo struck out five and walked three.
The Reds also received help from Ken Griffey Jr., who was back in the lineup after missing three of the last four games because of a chest problem. He went 3-for-3, with a home run and two RBI, for his first three-hit game of the season.
"He'd had five starts and four of them had been really good and we hadn't done anything for him," Griffey said. "I'm just glad that we were able to score some runs and let him go out there and enjoy something instead of us sitting there battling."
Reds manager Jerry Narron said he thought the time off might have helped Griffey's hand, which he broke in the offseason, feel better, but Griffey brushed off that theory.
"No, all that stuff hurts," he said, but added that he had recovered from his chest ailment and could finally breathe normally.
In the third, Houston starter Matt Albers gave up back-to-back homers to Griffey and Alex Gonzalez. Griffey's landed in the right field bleachers and the one by Gonzalez sailed to the Crawford Boxes in left field. Dunn reached first when Berkman couldn't handle his grounder.
Dunn stole second base before scoring on a single by David Ross. Arroyo singled before an RBI-single by Josh Hamilton that made it 6-0 chased Albers.
"It was really nice, especially to have a game that you knew was under control after you got through the fifth or sixth," Arroyo said. "I had the opportunity to go out there and just relax a little bit and pitch."
The Reds scored two runs in the second on an error by Lamb, the third baseman.
Albers (0-1) allowed eight hits and six runs -- three earned -- in 2 1/3 innings. He walked one and struck out two.
"He got the ball up, his ball was flat and he got behind," Astros manager Phil Garner said. "That's a bad combination."
Brian Moehler allowed one hit and struck out two in 2 2/3 innings.
Scott Hatteberg doubled in the sixth off reliever Trever Miller and scored on a single by Griffey. Gonzalez followed with a double before Dunn's three-run homer. It was Dunn's seventh homer and made it 10-1, causing a chorus of boos and sending scores of fans streaming for the exits.
Houston's former closer Brad Lidge allowed one hit and one run and hit one batter in 1 2/3 innings before being replaced by Dave Borkowski in the eighth.
Biggio tripled in the eighth for his 2,954th hit and scored on a single by Berkman. Carlos Lee then hit a grounder to Gonzalez who made an unassisted double play by tagging Lamb and stepping on second to put Berkman out.
"We didn't look very good or play very well," Biggio said. "Sometimes it gets uglier before it gets any better. Hopefully tonight will be the worst of it."
- Tuesday's game marked the second time this season the Reds have had back-to-back home runs after Brandon Phillips and Hamilton did it on April 10.
- Reds RHP Brad Salmon made his major league debut on Tuesday, allowing no hits or runs with one walk in the ninth.