TOKYO -- Florian Wellbrock of Germany added a gold medal in marathon swimming to his bronze at the pool, romping to a dominant win in the men's 10-kilometer race at Tokyo Bay in the Summer Olympics on Thursday.
Wellbrock sprinted out to an early lead, was up front most of the way and won by the biggest margin in Olympic marathon swimming history on another sweltering morning in Japan's capital.
"Florian was unbeatable today," said Kristof Rasovszky of Hungary, who finished more than 25 seconds behind for the silver. "I tried to be the best of the rest."
Even with the race starting at 6:30 a.m., the temperature was already 81 degrees with 80% humidity, making it feel like close to 90 degrees. Unlike the women's race the previous day, there were no clouds to mitigate the heat.
It sure didn't bother the reigning world champion.
"A little bit unreal," the 23-year-old Wellbrock said. "The first seven [kilometers] of this race felt really easy. My competitors had to work really hard behind me."
The stifling conditions got to David Aubry of France, who dropped out with about 3 kilometers remaining and was carried off the deck on a stretcher. French officials said a shoulder injury hampered his training leading up to the race, so his fitness wasn't good enough to handle the heat and Wellbrock's pace.
Aubry was feeling better after receiving treatment in the medical facility.
"It was really hot," Rasovszky said. "I tried to drink my refresher every lap and I managed to do it."
Hector Pardoe of Britain also failed to finish after being elbowed in the right eye. His goggles were knocked off, and he emerged from the water with a nasty gash and a swollen eye.
"My goggles were completely snapped off and I couldn't see a thing," Pardoe said. "I didn't realize how bad it was. It was all blurry in my eye."
Wellbrock pulled away on the final lap to win by 25.3 seconds, finishing in 1 hour, 48 minutes, 33.7 seconds. It was by far the largest margin of victory in the history of Olympic marathon swimming, which was added to the program at the 2008 Beijing Games.
Wellbrock also won a bronze in the 1,500-meter freestyle on the last day of swimming at the pool.
Rasovsky finished in 1:48.59.0, while Gregorio Paltrinieri of Italy picked up the bronze in 1:49.01.1. Paltrinieri was silver medalist in the 800 freestyle at the pool, completing a remarkable comeback from a bout with mononucleosis shortly before the games.
Wellbrock and Paltrinieri became the second and third swimmers to win both pool and open water medals at the Olympics, following Ous Mellouli of Tunisia.
Defending Olympic marathon champion Ferry Weertman of the Netherlands finished seventh, while American Jordan Wilimovsky was 10th.
Wellbrock stunned the field by opening up more than a 10-second lead in the first kilometer. Everyone else had to work hard just to keep up, which paid off at the end when no one had enough energy to mount a comeback.
"It was surprising," Paltrinieri said. "I didn't even notice (Wellbrock's big lead) until my coach told me I was about 30 seconds behind this guy. I started to close the gap a little bit, but it was really hard.
"Florian was on another planet today."
After Wellbrock made the final turn around a red buoy at the far end of the course, his coaches were already cheering and celebrating on the deck. They knew it was over.
Wellbrock slapped the timing pad, climbed from the water and sprawled out on the deck, pouring water on his chest under the blazing sun. He skipped a trip through the media mixed zone, heading straight to the recovery area, but was feeling just fine when he returned to receive his gold medal.
It was a far cry from the 2016 race at Rio de Janeiro, where Weertman beat Spyridon Gianniotis of Greece by just 0.7 seconds in a photo finish. The top 19 in that event all finished closer to the lead than Rasovsky's margin behind Wellbrock.
In three previous men's marathon races, the largest margin of victory was 3.4 seconds by Mellouli at the 2012 London Games.
Mellouli, competing in his sixth Olympics at age 37, finished 20th out of 24 swimmers who completed the race. He was nearly 8 minutes behind Wellbrock.