The series will continue in Atlanta on Saturday night.
On Friday, Atlanta seized a 4-0 lead without an extra-base hit before turning it on with two homers in the fourth inning.
"I'm really happy with our effort the entire season, our focus during the at-bats," Braves outfielder Ronald Acuna Jr. told Bally Sports through an interpreter.
"Honestly, we were talking about it in the dugout, saying, we're hitting the balls hard, but we're about to start hitting them harder."
Acuna went 3-for-4 with a homer and two RBIs and two runs in the series opener.
For the Braves, various flavors of offense could be a path to winning this series after they dropped one against the St. Louis Cardinals.
Pittsburgh and Atlanta split a four-game series a month ago, with each team scoring 25 runs. After that, the Braves reeled off seven straight series wins before dropping two of three games to the Cardinals.
Atlanta has a 15-game lead in the National League East but isn't currently coasting. The Braves had lost three consecutive contests before righting the ship in a strong way, stacking two eight-run games in a row.
Pittsburgh (65-76) has won three straight series, including taking two of three games from the NL Central-leading Milwaukee Brewers entering this series.
"They just did a good job putting the ball in play," Pirates manager Derek Shelton said. "You're seeing why they have 90 wins or whatever they have. Probably the best offense in baseball. One to nine, they just grind through at-bats."
Saturday, Pittsburgh right-hander Johan Oviedo (8-14, 4.27 ERA) is scheduled to start opposite Atlanta left-hander Dylan Dodd (2-1, 7.40).
Oviedo, the only other true Pirates starter aside from Keller at this point, is 5-3 with a 3.09 ERA over his past eight starts.
The past two have been opposite ends of the spectrum. Oviedo pitched a two-hit shutout Aug. 28 at Kansas City, then took a loss Sunday at St. Louis after giving up five runs (three earned) in 3 2/3 innings.
"I didn't feel comfortable with anything (Sunday)," said Oviedo, who also disclosed that he has been dealing with a measure of discomfort "a lot" this season.
"The worst part is it's out of my control. I just need to keep moving forward with it."
Fatigue could be a factor. Oviedo has reached a career high with 158 innings this year, and he racked up a personal-high 112 pitches in the gem against the Royals.
Oviedo has faced the Braves once, throwing 1 2/3 scoreless innings in relief on July 4, 2022, while pitching for St. Louis.
Dodd is expected to be recalled from Triple-A Gwinnett to make his sixth career major league appearance and his first start vs. the Pirates.
He began the season with Atlanta and won his MLB debut but was demoted after a couple of rough outings.
—Field Level Media