Needing work, Wagner pitched the ninth inning in the Braves' 7-1 loss to the Marlins at Turner Field and fanned rookie Mike Stanton for his 1,170th strikeout to pass Jesse Orosco.
But Wagner didn't keep the ball and declined to talk to talk to the media after the game.
"We lost," he said.
The 39-year-old plans to retire after the season. He has made 838 career relief appearances, including 56 for the Braves this year.
Wagner, who came back from Tommy John surgery last season, has been solid in his first season with Atlanta. He is 7-2 with a 1.65 ERA and has 30 saves in 37 opportunities, with 78 strikeouts to 17 walks in 54 2/3 innings.
Wagner walked two in the ninth against the Marlins, but got a double play to end the inning.