He became just the seventh pitcher to start a postseason game on zero days' rest, and the first to do so outside the World Series, according to Richard Justice of MLB.com.
Peacock needed eight pitches to complete the final inning of Friday night's game. He's the fourth pitcher to close one playoff game and start the next the following day. Firpo Marberry was the last to accomplish the feat during the 1924 World Series for the Washington Senators.
Pitchers who have been deployed on zero days' rest have a combined playoff record of 3-3.
"This guy has closed a playoff game," Astros manager AJ Hinch said before the game. "He has closed a World Series game. He's pitched a lot of games for us. His demeanor is great, his stuff is really good. I think he feels really good."
Peacock cruised through the first inning, getting three outs on seven pitches - all strikes. He ran into some trouble in the second, allowing a run on two hits. After issuing a walk with two outs and a runner on base, he was relieved by Josh James.
Peacock moved between the rotation and the bullpen this season while also spending time on the injured list. He went 7-6 with a 4.12 ERA over 91 2/3 innings. Friday was his first appearance of the postseason.