ATLANTA -- Andrelton Simmons believes winning close games in late September can only help the Braves in October.
It was Simmons' third game-ending hit of the season and the Braves' 24th win in their final at-bat. Simmons said it's a good habit for the NL East champions to carry into the playoffs.
"It's always good to have those close games and come out victorious and create that winning habit that we've had throughout the year," Simmons said. "To keep that going into the postseason is big."
Upton led off the ninth by hitting the first pitch from Donovan Hand (0-5) for a single to left. Freddie Freeman hit a fly ball to deep center for the first out before Evan Gattis, who had three hits, hit a grounder that Scooter Gennett bobbled behind second base for an infield hit, leaving runners at first and second.
The official scorer originally ruled Gennett's play an error before changing the call after the game.
Brian McCann popped out to third base for the second out before Simmons' first hit of the night ended the game.
"He's come up big in those situations," said Braves manager Fredi Gonzalez of Simmons, who is best known for his standout defense at shortstop.
Gonzalez said Simmons, 24, thrives in pressure situations.
"He's got a pretty good temperament and I just think he keeps getting better and better," Gonzalez said. "... We all know what kind of defender he is, and I think his bat is just going to keep getting better and better as he matures."
Craig Kimbrel (4-3), who leads the majors with 49 saves, struck out the side in the ninth. He has 96 strikeouts in 65 innings.
Shortstop Jeff Bianchi hit his first homer of the season in the fifth for Milwaukee.
Brewers rookie Tyler Thornburg set a career high with eight strikeouts while giving up two runs, seven hits and one walk in seven innings. Thornburg, 24, has allowed no more than two runs in any of his seven starts.
"You never feel good when you don't win a game, but he's got to feel good about what he did this season," Brewers manager Ron Roenicke said. "From a Triple-A start, that's quite a finish."
Thornburg was born in Houston but attended high school in the metro Atlanta area.
"Being from here, I tried to push the moment aside a little bit and to try to stick with what I've been doing," Thornburg said. "And it worked well tonight."
Thornburg had consecutive wins over the Cardinals and Cubs before facing the Braves. He also had strong starts against Texas and Pittsburgh.
"I know there are a lot of people out there that either don't think I belong or don't think I belong in the starting rotation," Thornburg said. "I did pitch against four playoff teams. It wasn't exactly bad teams I was facing. I'm really excited about that. That will give me a lot of confidence going into the offseason."
Freddy Garcia allowed two run, six hits and one walk in 6 2/3 innings for Atlanta. Garcia, 36, had seven strikeouts to set a season high in a combined 13 starts with Baltimore and the Braves.
Thornburg was helped by double plays in the second and third innings before giving up a run in the fourth. With two outs, Freeman singled and scored on a double to the base of the wall in center field by Gattis, who was thrown out trying to advance to third.
The Braves announced RHP David Hale will start Thursday night against Philadelphia. RHP Kris Medlen will have an extra day of rest before starting Friday night, followed by LHP Mike Minor and RHP Julio Teheran. Medlen, Minor and Teheran are in line to be the first three in the rotation for the playoffs, but Gonzalez said he's not yet ready to name Medlen the Game 1 starter. ... Brewers SS Jean Segura had to stop running before the game after he felt tightness in his strained right hamstring. ... Roenicke said RHP Wily Peralta, who developed a blister on his throwing hand in his last start against the Cardinals on Sunday night, will not make his scheduled start Saturday against the Mets. ... Braves LHP Paul Maholm and Brewers RHP Kyle Lohse will bring 10-10 records into Wednesday night's final game of the series.