PHILADELPHIA -- Adam Dunn snapped out of his slump in a big way.
Dunn hit a two-run shot in the fifth inning and a tiebreaking three-run drive off Jon Lieber (5-2) in the sixth for his third multihomer game of the season.
Ken Griffey Jr. also homered and had three hits for the Reds, who won for just the third time in 14 games.
"I kind of had an idea of how he was trying to pitch to me," said Dunn, who came in with five hits in his previous 36 at-bats. "I swung hard in case I hit them."
Bobby Abreu homered for the fifth straight game for the Phillies, who have lost three in a row to drop to 15-21.
Cincinnati's Ramon Ortiz (1-1) allowed three runs, eight hits and struck out five in five innings in his third start since returning from the disabled list after being out with a groin injury.
Danny Graves pitched the final inning for his ninth save in 11 chances.
"Thankfully the bullpen protected the lead," Graves said. "It definitely builds confidence."
Lieber gave up six runs and seven hits in 5 1/3 innings, his shortest outing of the season. He hadn't allowed more than three earned runs in his first seven starts.
Dunn followed with his 10th homer, a towering drive to center field that traveled 448 feet and nearly landed in the Reds' bullpen.
"Two bad pitches I left over the plate and he's a very good hitter," Lieber said.
Philadelphia had the bases loaded with no outs in the fifth, but only scored one run.
Jimmy Rollins started the inning with a triple and Placido Polanco and Abreu walked. Pat Burrell's grounder to third base scored Rollins and forced out Polanco at third, giving the Phillies a 3-2 lead.
The Phillies had two other runners thrown out on the bases. Burrell was out trying to stretch a single into a double in the third and Abreu was picked off first base in the first.
"We were aggressive, but we've got to be smarter," Phillies manager Charlie Manuel said. "We had some chances to get a big hit, but just couldn't do it."
Philadelphia got to 6-5 in the seventh on Burrell's RBI single and a passed ball by catcher Javier Valentin that allowed Abreu to score.
Griffey's solo homer off Rheal Cormier in the eighth gave the Reds a two-run cushion.
Abreu had an RBI single in the first and hit his eighth homer in the third.
Dunn tied it at 2 in the fifth with his two-run shot into the right-field seats.
"He's capable of getting on a roll like that," Reds manager Dave Miley said.
- Dick Allen (1969) and Mike Schmidt (1979) are the only other Phillies to homer in five straight games. The major league record is eight games by Dale Long (1956), Don Mattingly (1987) and Griffey (1993).
- The Reds are 4-11 on the road.
- Dunn has 12 multihomer games in his career.
- Griffey has homered in 39 major league stadiums.
- Phillies C Mike Lieberthal left the game after he was hit in the right ring finger by a pitch in the eighth. X-rays on the finger were negative. He's two plate appearances short of meeting a clause in his contract that would guarantee his salary for 2006 at $7.5 million.