After Atlanta blew a four-run lead, Heyward hit an RBI double with two outs in the ninth inning to give the Braves a 5-4 win over the Cincinnati Reds on Wednesday night.
Heyward doubled twice and also hit his first major league triple. The rookie helped the Braves end Cincinnati's four-game winning streak.
Martin Prado singled with two outs in the ninth off Nick Masset (3-2) and scored on Heyward's double to right field.
The Reds, who lead the NL with 13 comeback wins, scored three runs in the eighth and tied it in the ninth on pinch-hitter Chris Heisey's leadoff homer against Wagner (4-0). Wagner absorbed his second blown save in six chances but struck out Scott Rolen and Jay Bruce with runners on first and second to end the ninth.
Wagner then watched Heyward, the Braves' rookie star, end the game in the bottom of the inning.
"It doesn't surprise me anymore," Wagner said. "He's not 20, he's about a 10-year vet the way he carries himself and handles all the attention and the pressure that's put on him. It's great to play with him."
Braves manager Bobby Cox said "Heyward comes through again.
"He hit that last one really hard. He hit it so hard I didn't know if (Prado) could score from first."
Heyward made a dramatic first impression on Reds manager Dusty Baker.
"He looked great tonight," Baker said. "He looked outstanding. We'd heard a lot about him."
Heyward said his goal was to have an aggressive at-bat. He hit a high fastball from Masset into the right-field corner.
Heyward is known for his discipline and patience at the plate, but with two outs he said he was determined to swing at "anything close."
"Swing the bat," he said. "Try not to go down looking."