Obadele Thompson of UTEP, a rising star among the world's young sprinters, pulled up lame in the 200-meter semifinals Friday and is out of the NCAA Track and Field Championships.

The 20-year-old from Barbados, whose wind-aided 9.69-second effort earlier this year was the fastest 100 ever under any conditions, strained his right groin while winning his 100 semifinal heat in 10.17 seconds.Today's 100 final, which includes UCLA's Ato Boldon and Kentucky's Tim Harden, figured to be the premiere event of the four-day competition at the University of Oregon's Hayward Field, where the weather was sunny Friday and considerably warmer than it had been during the meet's first two days.

Boldon, from Trinidad, has the fastest time in the world this year at 9.93 and won his semifinal heat in a wind-aided 9.97 Friday. Harden, the defending champion, qualified fourth behind Boldon, Thompson and Alvis Whitted of North Carolina State.

Balazs Kiss won his fourth NCAA hammer championship at 265 feet, 3 inches, the longest throw in the world this year.

The 24-year-old Hungarian, competing for Southern California, became the fifth athlete to win four NCAA titles in the same event.

The most dramatic race in the meet thus far unfolded as darkness fell. In the 10,000, Arkansas teammates Godfrey Siamusiye and Jason Bunston engaged in a duel that saw them exchange lead three times, then run stride for stride the last five meters before Siamusiye barely edged ahead.

Siamusiye, the defending champion who also will run in the 5,000 today, used a 58.9-second final lap to win in 28:56.39, 16-hundredths of a second ahead of Bunston.

The 1-2 finish pushed favored Arkansas into the men's team lead with 31 points. North Carolina was second with 21, followed by George Mason with 20.

Louisiana State's women flirted with disaster in the 400-meter relay. LSU's D'Andre Hill, running the anchor, had to stutter-step to avoid stepping out of the exchange zone in taking the baton from Zundra Feagin. She managed to avoid disqualification and LSU won the event for the fifth consecutive time and seventh time in eight years.

The Lady Tigers' time of 43.03 was well off their 42.76 clocking in Wednesday's semifinals. That time was the second-fastest ever by a collegiate team.