Carpenter delivered a go-ahead, three-run double with two outs in the fourth to give the Cardinals their first lead since Monday.
"I think the spark part is really what you can't help but notice," manager Mike Matheny said of Carpenter. "When that guy is in the lineup, it changes a little bit. We needed a little change.
"It was a push to get him in there today. I absolutely applaud him and the training staff. They really worked hard on him and gave him a round of tests this morning that gave us the green light to do that."
Carpenter's sprained ankle had worsened enough on Friday that the club had him undergo X-rays to ensure that he didn't sustain a fracture. Those X-rays came back clean, and a day later, Carpenter unexpectedly had no limitations.
"The fact that I felt good enough to play was kind of surprising," Carpenter said. "I got to the point where I could get it done and I felt like I could play. I'm glad I was in there."
Carpenter arrived at Nationals Park before almost anyone on Saturday to begin that treatment and to put his ankle through some mobility tests.
His availability allowed Matheny the flexibility to give right fielder Carlos Beltran the day off. Even that residual effect was big. Beltran came off the bench with a game-tying RBI single in the eighth.
Carpenter sustained the ankle injury working on a double play turn at second base during pregame infield drills on Thursday. He has been taking work at second in case the Cardinals want to try him at the position again this season.
That defensive work, Carpenter said, will continue in earnest this offseason.
"I think it just goes back to kind of the same mentality I had coming into Spring Training," Carpenter said. "I look at what we have as a group and I have to try to find a fit. Next year, if I can get to the point where I can play good second base, I can play. It's more of just common sense.... I feel like I can do it, and I feel like that's my best chance to get in the lineup every day."