RIO DE JANEIRO -- Tom Daley thought he had the best shot at upsetting China in men's 10-meter platform diving.

He won't get the chance.

The British diver surprisingly failed to qualify for Saturday's Olympic final, finishing 18th and last in the semifinals after topping the preliminaries a day earlier. Daley botched his second and third dives, leaving him desperately trying to climb out of last place with two dives remaining.

The Chinese finished 1-2, with Chen Aisen leading the way and teammate Qui Bo second. Chen totalled 559.90 points and Qui had 504.70. Qui settled for silver four years ago in London, where he was upset by American David Boudia.

China is seeking its seventh gold in eight events at the Rio de Janeiro Games.

Ivan Garcia of Mexico was third at 497.55 and Benjamin Auffret of France fourth at 477.00. Boudia qualified 10th at 458.35, but American teammate Steele Johnson missed out on making the final by six points, finishing 13th. Scores don't carry over to the final.

Daley earned bronze on the 33-foot tower in front of partisan fans in London and had set his sights on knocking off the Chinese in Rio.

"I'm in shock right now," he said, tears welling in his brown eyes. "I'm the only one who could challenge the Chinese for that gold medal. In the Olympics, you can get your dreams crushed."

No one saw it coming, either.

Daley was stellar in Friday's prelims, finishing seven points ahead of second-place Qui. He consistently hit his dives and was confident in knowing he came into Rio in the best shape of his life.

Then disaster struck. He missed his second dive, falling from eighth to 17th. On his third dive -- usually his best -- he scored even lower.

"I've been feeling really, really good. In training, everything has been going really well," Daley said. "Right now it's just kind of heartbreaking to think that it just didn't happen for me today."

Daley's total of 403.25 was 168.60 points fewer than he had in the prelims.

"It was painful," his coach Jane Figueiredo said. "Sometimes you don't really understand what is happening. I know he was telling himself all the right things. It wasn't for lack of being fired up. It looked like he just didn't feel his body."

Daley rallied on his fourth and fifth dives to get back to 15th. But he faltered again on his last dive, a back 3 1/2 somersaults in which his slightly bent legs smashed the water.

Daley won't go home empty-handed. He and partner Daniel Goodfellow earned bronze in 10-meter synchronized platform.

He hasn't given up on his ultimate goal.

"I want to be the men's 10-meter platform Olympic champion," he said. "This has definitely given me a massive boost of motivation to want to get up there."