Eric Gay/Associated Press

For the second night in a row, Michael Phelps rose to the occasion at the Phillips 66 National Championships in San Antonio. The 30-year-old won the men's 100-meter butterfly in commanding fashion.

Phelps was banned for the 2015 FINA World Championships in Kazan, Russia, so the U.S. championships effectively served as his biggest showcase event ahead of the 2016 Olympics.

On Friday night, Phelps competed in the men's 200-meter butterfly, blowing the competition away in the finals heat. His final run of one minute, 52.94 seconds wasn't merely the best time of the night; it was the best time anybody has posted this year and narrowly bettered Chad Le Clos' gold-medal-winning time at the 2012 Summer Olympics.

"I don't know the Russian term, but probably, 'holy s--t,'" said Phelps' trainer Bob Bowman when asked how those in Kazan might have reacted to Phelps' performance, per ESPN.com's Wayne Drehs. "I think there will be some surprise. I think some people will be very, very surprised."

After Saturday night, a palpable sense of dread must be hanging over Phelps' biggest competition.

The 18-time gold medalist didn't get off to a great start—at least by his supreme standards. He paced himself during the preliminaries, finishing second to Jack Conger in the 100 with a time of 52.12 seconds:

Men's 100-Meter Butterfly—Top Preliminary Times Pos. Swimmer Time 1 Jack Conger 51.97 2 Michael Phelps 52.12 3 Matthew Josa 52.21 4 David Nolan 52.46 5 Giles Smith 52.66 6 Tripp Cooper 52.88 7 Connor Black 53.03 8 Braxston Timm 53.06 9 Carl Weigley 53.12 10 Long Gutierrez 53.13 Source: OmegaTiming.com

Phelps clearly saved his best for the finals, and his best is better than arguably anybody in the world right now.

He quickly swam out into the lead with a 50-meter split time of 24.10 seconds. The gulf between him and the rest of the field then grew during the final 50 meters, with everybody else fighting for second.

In the end, Phelps beat Conger by nearly a full second:

Men's 100-Meter Butterfly—Final A Pos. Swimmer Time 1 Michael Phelps 50.45 2 Jack Conger 51.33 3 David Nolan 52.15 4 Giles Smith 52.23 5 Matthew Josa 52.28 6 Connor Black 52.61 7 Tripp Cooper 52.63 8 Braxston Timm 53.38 Source: OmegaTiming.com

Yahoo Sports' Pat Forde was beyond impressed by what he saw in the pool from Phelps:

According to Swimming World, Phelps missed a world record by 0.63 seconds. His time is particularly notable given what Le Clos recently said at the world championships after swimming the 100 in 50.56 seconds.

"I just did a [100-meter butterfly] time that [Phelps] hasn't done in four years, so he can keep quiet now," Le Clos told Eurosport (via Olympic Talk's Nick Zaccardi).

Perhaps it's fair to wonder how Phelps would perform when pitted against the best in the world, Le Clos in particular. You wouldn't expect his times to suffer greatly, but maybe he loses a split-second or two that mean the difference between first and second.

Still, publicly challenging Phelps may not be a wise strategy for Le Clos going forward, especially after Phelps' butterfly victories in San Antonio.