French Open 2019 - Roger Federer masters Leonardo Mayer in the Roland Garros heat

Federer, who is making his first appearance in Paris since 2015, is still yet to drop a set on his way to the last eight after winning 6-2, 6-3, 6-3.

The Swiss led from the off, breaking Mayer in the first game and sprinting into a 5-1 lead, turning up the heat as temperatures hit the early 30s.

After sealing the first set in just over half an hour with an exquisite volley, he continued his imperious form with by breaking the Argentine in the opening game of the second, which he also won at a canter.

In the third, Mayer offered more resistance, forcing Federer to navigate a tricky service game and saving the first four break point chances the 37-year-old crafted. The Swiss took advantage of the fifth however, and cruised into the quarter-finals.

Federer will play either Stefanos Tsitsipas, who ended his Australian Open defence in January, or Stan Wawrinka, who famously beat him on in the quarter-finals at Roland Garros in 2015.

“I would definitely have to look back into how Stefanos plays on clay. Obviously he returns from further back, he's not so far in. But he moves very naturally on the clay surface. So he's coming in with tons of matches, as well, in the year but also on clay, with a great win against Rafa in Madrid,” Federer said.

Of Wawrinka he said: "On clay, it's been definitely more dangerous than on any other surface for me against him. I hope he's not at the level of '15, but we'll find out, because there he was crushing the ball. It was unbelievable."