Belgium's Remco Evenepoel made history on Saturday in the men's cycling road race, though Hong Kong's Vincent Lau dropped out almost three-quarters of the way through one of the most gruelling of all Olympic events.

Evenepoel, who won the time trial a week earlier, became the first man to claim gold in both road cycling disciplines, despite having to swap bikes four kilometres from the finish because of a mechanical failure.

He took control 15 kilometres from the end of the 273km race around Paris and surrounding areas to cross the finish line near the Eiffel Tower one minute and 11 seconds ahead of Valentin Madouas of France. Another home athlete, Christophe Laporte, completed the podium.

Lau pushed hard and cycled beyond the 200-kilometre mark, but he unfortunately couldn’t keep up with the peloton, becoming one of 13 participants who failed to complete the race.

He said he was disappointed he could not reach the finishing line, but he was excited to have raced alongside some all-time greats of the sport.

"Performance-wise, I think I could do better. But the experience, I think, it's the best you can get. A cycling race in France, it doesn't get bigger than this," Lau said.

"Seeing all the fans on every climb, shouting 'allez, allez, allez', it's every cyclist's dream to have that crowd on a climb cheering you on. I think the experience is very good."

The 90 cyclists in the pack had to overcome 2,800 metres of climbing on 13 ascents throughout the course, which passed many Parisian landmarks before winding into the French countryside.