Michael Phelps swam the 100-meter butterfly preliminary heats on Thursday afternoon, admitting that he screwed up the race in a pool-side interview.

"I somehow always screw it up," he said after the race.

Instead of advancing to the second semifinal, where Phelps would buy himself eight or so extra precious minutes after he races in the critical 200m individual medley final on Thursday night, he’ll be in the first one, he explained — potentially more tired on his quest for a four-peat.

Phelps won the 100-meter butterfly in the 2004, 2008 and 2012 Olympics.

Phelps raced to 51.60 seconds, good enough for fourth place overall. U.S. teammate Tom Shields, making his Olympic debut, clocked 51.58 and will also advance.