TOKYO (REUTERS) - Caeleb Dressel of the United States won the gold medal in the men's 100m freestyle at the Tokyo Olympics on Thursday (July 29).

The American won his second gold in Tokyo in an Olympic record time of 47.02sec ahead of defending champion Australian Kyle Chalmers (47.08sec) and Russian Kliment Kolesnikov (47.44sec).

Dressel, who could win seven golds in Tokyo, won his first in the men's 4x100m freestyle relay on Monday.

The Olympic gold was Dressel's fourth overall but his first in an individual event.

"I wasn't worried about anything at all," he said when asked about the close contest.

"It means a lot. I knew the weight was on my shoulders."

He said the victory in the individual event was sweeter.

"It is different and I know that now," he said.

"I didn't want to admit it. But it's up to yourself, there's no one to bail you out."

Meanwhile, with two astonishing late surges, American Bobby Finke won the inaugural men's 800m freestyle and Australia's Izaac Stubblety-Cook took the men's 200m breaststroke.

Finke pulled off a major upset by winning gold ahead of Italian world champion Gregorio Paltrinieri, who led all the way until the 750m turn when German Florian Wellbrock moved in front for the last length.

But Finke then made his late move and powered home in a time of 7min 41.87sec. Wellbrock faded but Paltrinieri did not, the Italian, who had been a doubt for the Games due to illness, touching 0.24 seconds behind Finke to take the silver.

Ukraine's Mykhailo Romanchuk took the bronze medal.

Finke said he had to push hard when he saw Paltrinieri was clawing his way back towards the finish.

"I noticed when I was about 10m out that he was catching a little ground and that was all the motivation I needed," said the American.

In the 200m breaststroke, Arno Kamminga of the Netherlands led at the 150m turn and was inside world record time as he fought with Finland's Matti Mattsson.

Stubbletly-Cook was third on the last turn, 1.2 seconds adrift of the lead, but then delivered an astonishing final lap to secure the country's fifth gold medal in the pool so far and the first for their men in 2:06.38, an Olympic record time.

Kamminga took the silver in 2:07.01sec while Mattsson was third in 2:07.13sec.

In the women's 200m butterfly, Zhang Yufei of China won the gold medal in another Olympic record time of 2:03.86sec. Regan Smith of the United States won the silver (2:05.30sec) and her compatriot Hali Flickinger took the bronze (2:06.65sec).