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.
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.
"It was important to win that game, no matter whether you come back or what, it's important to win that game after having a lead and losing it."
Heisey, also a rookie, said he "got lucky" on his first pinch-hit homer.
"He threw a fastball that was a strike and I just reacted," Heisey said. "It was the first time I'd ever faced Billy Wagner. He throws hard."
The Reds' comeback from a 4-0 deficit denied Kenshin Kawakami of his first win of 2010. Kawakami threw six scoreless innings, giving up five hits and one walk.
"The win's a win but the guy went out there and pitched six great innings and had a good opportunity and I hate that it didn't go his way," said Wagner of Kawakami, who has lost his first six decisions. "But at the end of the day, it was a good team win."
Cox said Kawakami pitched with a back strain after the second inning and had foot blisters while wearing new cleats. Kawakami could miss his next start, as the Braves had an off day on Monday.
Back-to-back doubles by Heyward and Jones drove in the first Atlanta run before McCann's homer.
Harang didn't allow another run until the fifth, when Heyward tripled and scored on Jones' single.
Reds second baseman Brandon Phillips remained in the game after he was shaken up while making a diving catch on Prado's short fly ball in shallow right field in the first. Phillips leaned forward on his knees for a minute after landing hard on his right shoulder.
Braves OF Matt Diaz is expected to be out one month or longer after having surgery on his infected right thumb. ... Baker said Jonny Gomes is his probable designated hitter when the Reds open an interleague series at Cleveland on Friday. ... Kawakami lowered his ERA from 5.79 to 4.98.