By Kari Lydersen
Gary Hall Jr. broke his Olympic Trials record from the morning with a blazing 21.91.
And right behind him was Anthony Ervin, qualifying second at 21.92.
Hall, 25, and Ervin, 19, both swim for Phoenix Swim Club.
Neil Walker, the 100 free champion, qualified third in 22.29, winning the first semi-final heat. Aaron Ciarla, 22 and swimming for Mecklenburg, qualified fourth in 22.36. Defending world champion Bill Pilczuk, 28, was fifth in 22.46. Matt Macedo was sixth in 22.52, Jason Lezak seventh in 22.57 and Christian Hasbach eighth in 22.71.
Hall had broken Matt Biondi's 1992 record of 22.12 in the morning with a 21.93.
For live results feeds check the OMEGA TIMING site.
Full results and schedule of events are available from US Swimming.
TV COVERAGE OF THE SWIM TRIALS
Olympic Swim Trials coverage on NBC:
Aug 19, 4-6 p.m. EST
Olympic Swim Trials coverage on PAX-TV:
Aug. 26, 9-11 p.m. ET and PT