Steven Bauer and Leonard Harvey Nitz of the G.S. Mengoni team combined to tire 7-Eleven's Alex Stieda and allow Bauer to win the $8,000 50-kilometer National Capital Open criterium bicycle race in a breakaway yesterday before a crowd of 2,000 on the White House Ellipse.

In the 30-kilometer women's event held earlier in the day, 7-Eleven's Rebecca Twigg coasted to an easy victory by 32 seconds in an accident-marred race in which one competitor, Vicky Brown, was admitted to George Washington University for overnight observation for a possible concussion.

Bauer, who registered so late for the race his name wasn't included in the program, broke away from a five-man pack with a little more than 10 kilometers to go. Nitz and Stieda hung close, however, and Stieda, who first took the lead with 23 laps to go, regained the advantage with six laps left. But Bauer quickly battled back to open up a 30-foot lead. He won by about a half-kilometer in 1:07.10.

"The wind was a real help on the backstretch," said Bauer. "You could just tuck yourself along the fence and it pushed you along. I caught Alex and Leonard at just the right time, and it was a real help to have a teammate there. We were able to work on Alex together, and luckily I broke at the right time."

Just as Bauer and Nitz were able to jointly tire Stieda in the stretch, the 21-year old 7-Eleven racer suffered from the lack of support by his teammate, Ron Hayman, who finished ninth.

"I had to keep chasing Bauer down," said Stieda, who is a member of the Canadian Olympic team. "I figured I'd keep him close, and Ron could control Nitz. But Ron got caught in the pack and wasn't able to help me. In a race like this it's good to break away, because a lot of the less-able racers can really hold you back."

It was only the second breakaway victory, which drew the pack out greatly, in the 14-year history of the race. Nitz narrowly beat Stieda for second, and the winner the past two years, Bruce Donaghy of Stowe/Shimano, finished a distant fourth. England's Alaric Gayfer, riding for Shimano Team Brooklyn, was fifth.

In the women's race, Twigg overcame a spectacular accident on the sixth lap to coast to victory by more than a half-kilometer. The wheels on the bikes of Brown and Louise Olson became crossed, throwing both riders and entangling several others. Brown, who was knocked unconscious in the fall, and Olson were taken to George Washington University Hospital, although Olson refused treatment and was released, according to the D.C. Fire Department paramedics who took her there. Brown regained consciousness in the ambulance, but suffered a possible concussion and is being held overnight for observation, according to the paramedics. A hospital spokesman would say only that Brown's condition was stable.

Twigg, 18, who left last night for a three-week tour of France with the Canadian Olympic team, quickly took over the lead after the 20-minute delay and easily outdistanced the competition.