Duda doubled with two out in the fourth, getting stranded on d'Arnaud's strikeout, but his average dropped to .169 in 59 at-bats with runners in scoring position.
Gattis, who went 3 for 3, spent the previous three days at Triple-A Gwinnett to get some at-bats. The NL's rookie of the month winner for April and May had slumped in August, but he seemed to correct his issues by going 6 for 13 in three games at Gwinnett.
Gattis took four pitches from Torres before crushing a cutter into the seats in left-center field. It was his first homer since the Braves' 8-2 victory at New York on July 24 — a span of 70 at-bats.
"It's good to square the ball up, first," Gattis said. "It just ended up being a home run, you know."
Atlanta has won 29 of its last 38 games and has rallied for 41 victories, best in the NL.
Notes: Braves manager Fredi Gonzalez said RF Jason Heyward, on the 15-day disabled list with a broken jaw, met with a doctor Tuesday and has been cleared to play catch and hit balls off a tee. ... Medlen is 2-1 with a 3.20 ERA and has 29 strikeouts in 25 1-3 innings in four starts against the Mets this year. ... Collins said before the game that he expects RHP Daisuke Matsuzaka will make his next scheduled start Sunday at Cleveland. Matsuzaka is 0-3 with a 10.95 ERA in three starts with New York. ... Collins added 1B Ike Davis, sidelined for the fourth straight with a strained right oblique, was in New York to see a doctor. ... Braves OF Jordan Schafer grounded out as a pinch-hitter for Medlen in the seventh. Schafer went 4 for 5 on Monday before leaving the game early with a sore back.