The United States suffered a bittersweet start to swimming at the World Swimming Championships today, and Nicole Haislett tasted both the bitter and the sweet.

The 17-year-old from St. Petersburg, Florida, won the first gold medal of the championships for the United States in the women's 100-meter freestyle but later lost a gold when judges said she jumped seven-hudredths of a second too early on the second leg of the 800 freestyle relay and disqualified the U.S. team.That gave the title to Germany and ended a night of record-breaking performances - and deep disappointment - for the Americans, who are favored to win both men's and women's team titles.

Hungarian unknown Norbert Rozsa broke the world record in the men's 100-meter breaststroke, and Chinese star Lin Li spoiled an expected American showdown in the women's 400-meter medley.

Rozsa, ranked 22nd in the world, lowered the world record to 1 minute, 1.45 seconds, .04 seconds faster than the mark he tied during morning heats.

The eagerly awaited rematch between Americans Summer Sanders and Janet Evans in the 400 IM, a highlight of last year's Goodwill Games, instead turned into a race for third between two tiring swimmers.

Nationally . . .