During the last 50 meters of the 100m backstroke this evening, Natalie Coughlin was dreaming of barbeque.

It had been a long day, and all she wanted to do was finish with a decent swim, get some pulled pork (from the Columbia restaurant Bandana's B-B-Q) and a good night's sleep.

Because she had already decided she wasn't going to swim in Monday's final, she wasn't even going to warm down. Mentally, she was already somewhere else.

"I was like barbeque and no warm down, barbeque and no warm down," Coughlin said. "It was a strange race. I really don't know what to say about it."

When she touched the wall and looked at the scoreboard, she thought it was a mistake.

59.21.

A world record.

In the preliminaries.

The Mizzou Aquatic Center couldn't believe it either. Katie Hoff jumped out of her seat. Michael Phelps' jaw dropped. Coaches were double checking their sheets, trying to figure out what had just happened. Coughlin's initial 50 split wasn't even that fast for her standards: 28.77. When she went 54.44 in Melbourne at the World Championships to set the previous mark, she swam the first 50 in 28.30.

"I had zero emotion going into that race," Coughlin said. "I was like 'It's prelims. I hope I go under 1:01.' I just wanted to have a solid swim in the backstroke before I go home. I haven't even done any backstroke since November, and that was short course. I just don't know."

While Coughlin couldn't stop shaking her head, Mark Schubert, the head coach of the U.S. National Team, couldn't stop smiling.

"I've watched Natalie for a lot of years and I've never seen her so surprised," Schubert said. "I talked to her afterward and she said 'I was looking at the scoreboard and I thought it was wrong. I thought it was a mistake.' She just built the race. She was out four-tenths slower than her world record split, so maybe she learned a little something about how to swim it."

Just earlier in the day, Coughlin said she really didn't even care about her times this early in the season. She just wanted to slowly build in preparation for U.S. Trials in July.

"I've set personal bests in the prelims before, but never in my strongest stroke," Coughlin said. "Just in events that I swim like once every few years. So that was highly unusual."

So was she saving her best swim for her last event of the meet?

"Not purposely," Coughlin said. "It must have been the barbeque. ... There is going to be lots of barbeque tonight. I'm going to go overboard."