Florida senior Caeleb Dressel won the 50-yard free in a time of 17.63 seconds Thursday night, taking almost half a second off the mark he had set earlier in the day at the NCAA Swimming and Diving Championships in Minneapolis.
Dressel's time of 17.63 beat the previous American, NCAA, U.S. Open and Florida record of 18.11 seconds, which Dressel had set in a prelim earlier in the day.
NC State's Ryan Held was second, finishing more than a second behind Dressel in 18.64. Minnesota's Bowen Becker was third.
It was a day of breaking records for Dressel. Before the 50 final, he swam a 17.81 split in his lead-off leg of the 200 freestyle relay, becoming the first man ever to break 18 seconds from a flat start. USC's Vlad Morozov is the only other man to have broken 18 from a relay start with his 17.86 from the 2013 NCAA meet.
Dressel, 21, owns all 10 of the all-time top 10 performances in the men's 50 free. He's a four-time winner in the event at the NCAA championships.