"If we didn't have Chase, we wouldn't be where we're at," Phillies manager Charlie Manuel said.
The Phillies offense roared to life in the fourth inning, when Geoff Jenkins led off with a double. Feliz and Coste then launched back-to-back home runs to give the Phillies a 5-1 lead.
Starter Kyle Kendrick allowed only two runs through the fifth inning on home runs to Jay Bruce and Edwin Encarnacion.
But Manuel saw the right-hander running into some trouble in the sixth. Kendrick allowed a leadoff single to Jerry Hairston Jr. Two batters later, Jay Bruce followed with a base hit.
Kendrick had thrown only 70 pitches up to that point, but Manuel thought that the Reds offense was starting to get to the 23-year-old.
"They were hitting some balls hard on him," Manuel said. "That was a good place to get him. He had pitched five [innings], and I didn't want him to lose the game."
Chad Durbin came on in relief and allowed Kendrick's two runners to score on an Adam Dunn double, trimming the Phillies' lead to one run.
Fortunately for Kendrick, the Phillies bullpen on Monday remained true to its usual 2008 form. Durbin stayed in the game to pitch a scoreless seventh.
Tom Gordon then took the hill in the eighth with the task of protecting a one-run lead while facing the Reds' two-, three- and four-hole hitters. In 14 pitches, Gordon elicited two pop ups from Ryan Freel and Bruce and struck out Brandon Phillips to complete a 1-2-3 inning.
By that point, it was a bullpen battle. The Phillies were unable to add any insurance runs in the eighth and entrusted their one-run lead to Brad Lidge in the ninth. Lidge retired the Reds in order for his 14th save in as many opportunities.
Much to Kendrick's delight.
"As a starter, your job is to keep your team in the game, and I was a little frustrated," he said. "As long as we win, I'm happy."