Chardy defeated fellow countryman Gilles Simon, a semi-finalist in the 2012 edition, 6-3, 6-0 in 66 minutes.

Mahut was forced to dig far deeper to defeat Canadian Vasek Pospisil 5-7, 7-5, 7-6(4).

“I feel good physically and I have a lot of energy,” he said. 

“I was serving better and moving better."

It was a less successful day for the United States as Steve Johnson and Ryan Harrison each made early exits.

Dutchman Robin Haase swept past Johnson 6-2, 6-1 in 51 minutes, while German lucky loser Peter Gojowczyk defeated Harrison 7-6(5), 6-3 in 85 minutes.

South Korea's Chung Hyeon thrashed Mischa Zverev of Germany 6-0, 6-2 and will now have the ominous task of facing top seed Rafael Nadal of Spain tomorrow.

A win for Nadal will see him guaranteed to end the year as world number one following the withdraw of Roger Federer as a withdrawal to rest his back.

Tomorrow will also see the start of the Women's Tennis Association Elite Trophy at the Hengqin Tennis Centre in Zhuhai, China.

The event featured players ranked ninth to 19th in the WTA rankings as well as one wildcard. 

France's Kristina Mladenovic will start as top seed.