Turns out, those comparisons to Michael Phelps weren't far-fetched at all when it comes to Leon Marchand.

They certainly weren't a burden for the 22-year-old Frenchman.

Marchand completed one of the most audacious doubles in swimming history on Wednesday night, winning the 200-meter butterfly and the 200 breaststroke about two hours apart, in front of a home crowd cheering his every stroke.

Two grueling races. Two very different strokes. Two Olympic records. Two gold medals.

Phelps, who won several doubles of his own while claiming a record eight golds at the 2008 Beijing Olympics, was duly impressed.

"That's probably the greatest double I've ever seen in the history of the sport," Phelps said while appearing on NBC's Olympics coverage in the United States. "The cheer, the electricity... I can't wait to talk to him to hear what it felt like."

"I'm a really shy person," Marchand said. "I was kind of the center of attention during those two races. I was trying to get the energy from the whole crowd. They're amazing to me, pushing me in every final."

The five-time world champion, little known outside the world of swimming before the Olympics, has become a national hero in the space of a week with his trio of golds.

"I've fulfilled a lot of dreams since I've been here. Doing this double was something I felt I could do, but to really do it, that's something else," he said.

"Of course, I had a lot of doubts, because everyone told me it wasn't possible," he said of the unprecedented double.

While the 15,000 crowd at the Paris La Defense Arena belted out a rousing rendition of La Marseillaise during the medal ceremonies, a smiling Marchand looked calm as he soaked up the adulation.

"I'm just trying to keep going. I really enjoyed every moment of those two finals. It was really amazing for me to swim those," he said, after dethroning two defending champions.

Thrilling the French fans and claiming the spotlight, even on a night when Katie Ledecky romped to another gold medal, Marchand notched up his second and third victories in the Paris pool and stamped himself — with the Olympics not even a week old — as one of the faces of the Games.

Trailing most of the way in the 200 fly, Marchand surged past the Hungarian world-record holder and defending Olympic champion Kristof Milak on the final lap to finish with an Olympic record of 1:51.71, touching first by just four-hundredths of a second.

Marchand's final lap was nearly 0.66 faster than anyone else in the field — and 1.26 clear of Milak.

"I've been watching so many races of his," Marchand said. "I know he has a lot of speed, way more than me, so I was just trying to get as close as possible, and then just push it until the end."

The bronze went to Canada's Ilya Kharun.

After rallying to beat Milak in the 200 fly with a finishing kick for the ages, Marchand made it look easy in the 200 breaststroke.

He led all the way, touching in 2 minutes, 5.85 seconds, as the fans — many holding up cardboard cutouts of his smiling face — nearly blew the roof off the arena.

Following on from his dominant victory in the 400 individual medley (IM) on Sunday, Marchand waved one finger and shook his head just a bit, as if he couldn't quite believe what he had done.

Then, he hustled off the deck to another rousing cheer to begin his warm down, before returning for the medal ceremony.

After another boisterous rendition of La Marseillaise, the other two medalists walked slowly around the pool, getting their pictures taken.

Not Marchand. He hustled back to the practice pool. There's still the 200m IM to win.

Agencies