Updated August 20, 2008

(AP Photo/Ivan Sekretarev)

BEIJING (AP) The stands were filled with fans, cheering for both every jump and crash. The theme from "Rocky" and AC/DC's "Thunderstruck" blared from speakers as Chinese cheerleaders and breakdancers gyrated along. Outside, plenty of people without tickets tried desperately to talk their way in, just to be part of it all.

It was nothing like the BMX world had ever seen. The sport finally had reached the Olympic stage.

"You can't get much more rad than this," American star Donny Robinson said.

Not in the Summer Games, anyway.

And in the biggest competition of their lives, the four American riders didn't disappoint - but didn't escape unscathed, either. All advanced, but three-time world champion Kyle Bennett dislocated his left shoulder in his third and final heat. Doctors popped it back into place, and Bennett plans to race Thursday.

U.S. Olympic trials champion Mike Day had the fastest time in the men's seeding time trial and easily won all three of his qualifying races, suggesting he's in gold-medal form. The lone American woman, Jill Kintner, moved into Thursday's semifinals seeded seventh in her field of 16.

"I had a great day," Day said. "Not to sound cocky, but everything's kind of coming naturally. Everything feels good, so hopefully tomorrow will be the same. I felt good and hopefully I made a statement today."

Bennett fell when Dutch racer Raymon van der Biezen lost control and remained on the track for several minutes, then pedaled across the finish line with his left arm pinned to his chest.

"For as gnarly as that crashed looked, I know Kyle will be back tomorrow for sure," Robinson said. "He finished the lap. Not everybody would do that."

Robinson, who won on the Beijing course last year in its debut event, crashed in his first quarterfinal race, putting his Olympic hopes in peril. But he finished second in the next heat and held on in the third race to earn his spot on Thursday's card.

"I needed to be consistent and it worked out," Robinson said.

BMX, or bicycle motocross, was started in California about 40 years ago, and even some of its most ardent followers were stunned when the International Olympic Committee decided to add it for the Beijing program, hoping it would provide a spark much in the same fashion that snowboarding did for the Winter Olympics.

If Day 1 was any indication, the IOC's plan is working.

"We're all excited to be here," Day said. "It's a huge step for BMX. If you could pick one stage to be on, it'd be the Olympic stage. And I know I've been thinking about it for 3½ years."

The crowd began arriving before 8 a.m., crammed into every open space in the venue's souvenir shop - "Give me BMX anything," one man draped in a New Zealand flag implored a worker there - and even the racers acknowledged taking a few seconds to soak in the scene.

"You take a look around and see what it all is, and get a little perspective," Kintner said. "It helps."

For the better part of a week, it had been mostly fun and games for the U.S. BMX crew.

Bennett broke the pedal off a rickshaw he borrowed while filming a spot for NBC in downtown Beijing. Kintner posed for a photo with famed gymnastics coach Bela Karolyi and watched Usain Bolt win the 100-meter dash. Day kept a constant lookout for basketball stars LeBron James and Kobe Bryant, both of whom are expected at Thursday's medal races.

"I hope they come," said Day, a Southern California guy and a diehard Lakers fan. "It'd be awesome if Kobe comes out. The whole experience has been so overwhelming."

But on Wednesday, it was all business.

"This is a once-in-a-lifetime thing and I find that the more experiences you take in, the better you are as a person," Kintner said. "You can't miss the games. We saw the 100 meters. How unreal is that? Fastest man alive!"

Kintner took anything but a direct route to the Olympic BMX world. She was a BMX champion as a kid, then turned her attention the sport of mountain-cross, a genre of mountain biking where she was a world champion - but when BMX got added to the Olympic program, she came back to the little bike.

And on Wednesday, Kintner couldn't help but marvel.

"Just the fact that other athletes are talking about it, and they're like, 'That's the most exciting thing,'" said Kintner, who's racing with a shredded knee ligament. "A lot of people are talking about it. People recognize me in the village. I'm like, wow, that's kind of weird."

Racers start by navigating a 35-foot, sharply banked ramp, and how well they come off that hill essentially sets up how they'll do on the rest of the course, which features hazards like steep turns, a 40-foot crevasse for the men to jump and moguls so tightly stacked together that one slip simply destroys momentum for the rest of the run.

There's no room for error, and having eight riders together in the heats often leads to spills - a lesson Robinson and Bennett learned once again Wednesday.

"After that first lap, there was nothing to lose. I either did it or didn't do it," Robinson said. "I've cried a bunch because of how much this means to me. It's not preparing anymore. It's here. I'm here to do it. Either greatness is going to happen, or it's back to normal life."