SYDNEY – The unthinkable happened to the unsinkable.

In a titanic surprise, Ian Thorpe could not muster the killer kick he had unleashed as the anchorman in a stirring Australian relay victory Saturday over the United States. That brought a packed house at the Sydney International Aquatic Centre that had been chanting and dancing to disbelieving silence today as their favorite son proved to have size 17 feet of clay.

Dutchman Pieter van den Hoogenband torpedoed the Thorpedo’s quest for four gold medals at these Olympics by winning the 200-meter freestyle. Van den Hoogenband tied the world record of 1:45.35 he set in Sunday’s semifinals. The general analysis in the host country was that Thorpe was conserving himself in the heats, and would break out with a world-record victory in the finals.

After all, before the heats, Thorpe had produced the five fastest times ever at this distance, all in this pool. That combination along with the energy mustered from Saturday when Thorpe became an Australian legend at 17 by winning the 400 free in world record time and anchoring the 4×100 world record triumph over the nemesis Americans appeared to make him invulnerable to even a peaking challenger. But Thorpe conceded the amount of swimming he already has done at these Games and all the hullabaloo around him could have sapped him some for the 200.

“I’m pretty happy with how I raced,” Thorpe said. “I have to feel happy if I put everything into the preparation and the race, and I am satisfied that I gave it my best shot.”

It was the first time Thorpe has not won in 17 months. Over the last 1 ½ years, his stature has grown to the point where he already was being labeled the swimmer of the 21st century. He was shooting for four gold medals here, something no Australian athlete has done in any Olympics. But now with two golds and a silver, the best he could hope is to add one more win in the 4×200 relay.

This triumph is going to provide van den Hoogenband a reputation as a giant killer. At the 1999 European Championships, he defeated Olympic champion Alex Popov in both the 50 and 100 freestyles. But his victory over Thorpe is of a different magnitude. This had seemed Thorpe’s pool. Thorpe’s Olympics. Thorpe’s time.

“I told Pieter how inspirational his swim was,” said American Lenny Krayzelburg, who won his 100 backstroke gold shortly after watching van den Hoogenband’s triumph. “He was a big underdog. He showed it’s not over until you swim the race.”

And it was quite a race. The women’s 100-meter backstroke was the first event on the evening program, but the buzz already was building for the second race. As the 200 freestylers emerged, the crowd erupted in cheers and camera flashes. Thorpe is Jordan big in Australia, a reality only deepened by his success Saturday.

Over the first 100 meters of the race, van den Hoogenband and Thorpe were joined by American Josh Davis. But then the two leaders pulled away, flipping at 150 meters in near synchronicity. Cheers of “Thorpey, Thorpey” ricocheted through the arena. But this time, the man-child could not use that as fuel. It was van den Hoogenband who pulled ahead in the final 30 meters.

“I don’t realize yet what I have achieved,” van den Hoogenband said. “I enjoyed every stroke of it.”

Van den Hoogenband claimed not to be intimidated by Thorpe’s success, saying he derived motivation in his training from it.

“I wanted to get the best out of this body,” he said. “I did not want to look at him. Only after I pushed off the last wall did I think, ‘I really want the gold medal.'”

He got it. The unsinkable sank.