Watch Michael Phelps Crush Simone Biles and Aly Raisman on Lip Sync Battle

Olivia Munn had a few secret weapons up her sleeve when she performed on Sunday’s Lip Sync Battle—Olympic gold medalists Simone Biles and Aly Raisman, who dominated the gymnastics competition at this year’s games. The athletes helped Team USA win big at the Rio Olympics and they also assisted Munn in a memorable version of Sia’s “Cheap Thrills” during a special episode.

Raisman and Biles weren’t the only Olympic gold medalists on the Lip Sync Battle stage: gold medalist and world-renowned swimmer, Michael Phelps was already scheduled to appear on the show, which is what inspired Munn to bring in her back-up. “When I found out that Michael Phelps was joining our set, I said the only way to beat a gold medal champion is to bring two gold medal champions,” Munn told host LL Cool J. Watch their performance below.

While Munn and Team USA’s gymnasts delivered an impressive performance, they couldn’t stop the unstoppable force of Phelps with his game face on. At the end of the night the home audience gave the gold to Phelps. Here’s his medal-worthy performance of Eminem’s “Lose Yourself”:

“Cheap Thrills”