AUSTIN, TEX., AUG. 2 -- Jeff Rouse became only the second American to swim the 100-meter backstroke under 55 seconds when he touched in 54.79 tonight in the long course national championships.

Rouse's effort in the preliminaries fell short of David Berkoff's world record of 54.51 set at the 1988 Olympics.

In Seoul, Berkoff set the mark in the preliminaries, but finished second in the final. Rouse avoided a similar situation, winning in 55.86.

Janet Evans, the world record holder in the women's 800-meter freestyle, did not have to struggle in winning the event. Her time of 8 minutes 24.32 seconds was the world's fastest this year and beat Erika Hansen by almost 13 seconds. The previous world best was 8:27.47, recorded by Evans here last week.

Summer Sanders won the women's 200-meter individual medley in 2:14.36. Her preliminary time of 2:14.06 is the fastest in the world this year.

Tom Jager, the world record holder in the 50-meter freestyle, won the event in 22.26. It was the third-fastest time in the world this year.

Jager, a silver medalist in the 1988 Olympics, set the world record of 21.81 earlier this year at the U.S. sprint championships.

Wednesday night, Mike Barrowman of Potomac, Md., missed breaking his own world record in the 200-meter breaststroke by two hundredths of a second. His time was 2 minutes 11.55 seconds.