In one of the coolest sideshows to a college sport event you’ll ever see, national swimming icons Michael Phelps, Matt Grevers and David Nolan went head-to-head-to-head in an exhibition 100 IM at the Arizona State-Arizona dual meet Saturday.

All three are professional swimmers training in the state of Arizona for the 2016 U.S. Olympic Trials and 2016 Rio de Janeiro Olympic Games.

Phelps, of course, is swimming’s most famous name, the most decorated Olympian in history and the man with the fastest 200 meter IM time worldwide last year. Grevers is the defending Olympic gold medalist in the 100 backstroke, and Nolan became the fastest short course yards 200 IMer in history at last winter’s NCAA Championships.

The college rivalry extended into the professional ranks at this meet – Phelps and Nolan train with the professional contingent at Arizona State, while Grevers is based out the University of Arizona as part of the Tucson Ford Dealer Aquatic club.

The race ultimately went to Grevers in 47.06, with Phelps going 47.47 for second and Nolan 47.65 for third. The ASU contingent got their revenge in the college dual, though, where the Sun Devil men topped Arizona for the first time since 2002.

Phelps also told SwimSwam that this 100 IM would be the last short course yards race of his career. Phelps has said he plans to retire for good after this summer’s Rio Olympic Games.

You can check out video of the race above, courtesy of Garrett McCaffrey. Of the five swimmers in the race, Phelps is in the middle lane, with Grevers one lane closer to the camera and Nolan one lane further away. You can also get a unique angle in the second video below – it alternates between over-water and underwater views of the battle.