Bagwell smacked a go-ahead three-run homer and Hidalgo added two solo shots as the
defeated the Reds for an eighth straight meeting, 5-3.
It was Houston's eighth win in nine games.
The Reds lost Griffey for the rest of the season in Thursday's series-opening setback. The oft-injured center fielder ruptured a tendon in his right ankle rounding first base on a double and underwent successful surgery Friday afternoon.
"It is hard to come in here and joke around and listen to music like we used to do," Reds starter
said. "With him gone, we just have to make the best of it."
Cincinnati scored the game's first run on
's 17th home run off
(6-5) in the second inning, but Houston took the lead for good one frame later on Bagwell's 18th homer, a two-out shot to right-center on a 2-0 offering from Dempster (3-7).
"A three-run homer is better than a solo home run," Bagwell said. "The ball carries to right here, but it carried great in Cinergy (Field), too. Cincinnati has been a good hitting town."
It was Bagwell's 398th career homer, moving him into a tie with
for 36th on the all-time list. He has hit 40 of his homers against the Reds, by far his most against any opponent.
Hidalgo made it 4-1 with a homer in the fourth and gave Oswalt a four-run cushion with his second blast of the contest two frames later. It was the ninth career two-homer game and second of the season for Hidalgo, who also singled in the second and eighth innings to tie his career high for hits.
"I've been hitting pretty good the last two games," said Hidalgo, who went 4-for-4 after collecting three hits Thursday. "This ballpark is pretty nice - the ball carries a lot. It's a nice place to hit."
Cincinnati pulled within 5-3 on back-to-back solo homers by
and pinch hitter
in the sixth inning but could not break through thereafter.
Oswalt allowed three runs and six hits in 6 2/3 innings to improve to 8-0 in 11 lifetime games - including nine starts - against the Reds.
pitched the ninth for his 27th save in 30 opportunities.
"My velocity is down a little bit, but it's only my third start in two months," said Oswalt, who is recovering from a right groin injury. "My velocity wasn't there. I had pretty good command, so I worked off the plate a little bit."
"Oswalt pitched well," Astros manager
said. "He had good off-speed stuff."
Dempster lost for the third time in four starts as he surrendered five runs and eight hits in six innings.
"(Houston) has a good lineup and you can't make many mistakes," Dempster said. "I made a couple tonight, but my slider's back and I have a whole second half to look forward to."
"On Bagwell, he tried to go down and away and left it up," Boone said of Dempster. "We've seen (Bagwell) hit it there before. He walked (
) in front of Bagwell. Other than that, he pitched pretty well. You're just not allowed to make many mistakes in this league."
Blum went 0-for-4 to halt his career-high hitting streak at 16 games.
exited the contest in the sixth inning after getting hit on the right hand by Dempster. X-rays were negative.