The Irish (25-6) will play DePaul on Monday night in the semifinals. It will be a rematch of last Monday night's game in which the Blue Demons scored with about 6 seconds left to edge the Irish by one point. That win earned DePaul the No. 2 seed in the tournament.
With top-seeded UConn and fourth seed Rutgers advancing it will be only the third time in the past decade that the top four seeds advanced to the semifinals.
Leading 26-24 with 2 minutes left in the first half, Peters keyed a 22-5 spurt over the next 8 minutes to help the Irish take control.
Louisville could only get within six the rest of the game.
Shoni Schimmel scored 12 to lead the Cardinals (20-12).