The Penguins appeared headed for a win in regulation when they erased a 2-1 deficit with third-period goals by Chris Conner and Deryk Engelland. Carolina tied it on a wraparound shot with 2:29 left in regulation by Drayson Bowman.
The win went to Mark-Andre Fleury, who made 31 saves in what was the 500th appearance of his career.
Carolina has lost four in a row and seven out of eight. Peters suffered the setback while stopping 22 shots.
Pittsburgh's Sidney Crosby scored 16 seconds into the middle period to bring about a 1-1 tie. It was his 21st of the campaign, moving him past Chris Kunitz for the team lead and putting him in fifth place on the NHL's goal scoring list.