Twelve-time French Open champion Rafael Nadal raced into the quarter-finals with a straight-set victory over American qualifier Sebastian Korda.

Spanish second seed Nadal, chasing a fourth successive title at Roland Garros, took the match 6-1 6-1 6-2.

He will face Jannik Sinner next after the Italian beat Alexander Zverev.

The 19-year-old, ranked 75 in the world, put in a superb performance to beat the US Open finalist 6-3 6-3 4-6 6-3.

I shouldn’t have played – Zverev

German sixth seed Zverev said after the match that he was “sick” with a fever and probably should not have played.

The 23-year-old called the doctor on court and showed them his throat and later took a tablet at a change of ends.

He told reporters he had had a temperature of 38 Celsius during the night after his previous match against Marco Cecchinato on Friday.

“I’m completely sick. I can’t really breathe, as you can hear by my voice. I had fever as well,” he said in his post-match news conference.

“I’m not in the best physical state. I warmed up today. I shouldn’t have played.”

Both Sinner and Zverev lost five-set matches at the US Open from two sets up – Sinner in the first round against Karen Khachanov, while Zverev did so in agonising fashion in the final against Dominic Thiem.

The Italian took advantage of a passive Zverev, hitting 39 winners to the sixth seed’s 20.

Sinner is the first player since Nadal in 2005 to reach the French Open quarter-finals in his main draw debut.

Analysis

BBC tennis correspondent Russell Fuller at Roland Garros

At last month’s US Open, players were not allowed to board the bus to Flushing Meadows until they had passed a temperature test and completed a health questionnaire.

The rules do not appear as stringent at the French Open, although the players are being regularly tested for Covid-19.

The question, therefore, for all of us here, is what should we do if feeling unwell?

The health and safety protocol issued to all accredited people calls for a “sense of duty and responsibility”.

It says: “Anyone showing symptoms – fever, dry cough, breathing difficulties, muscle pains, severe fatigue, loss of taste and/or smell, diarrhoea – must adopt a responsible attitude and not attend the stadium.”

Korda gets lesson from hero Nadal

Korda, whose dad Petr was the 1998 Australian Open champion and reached the final in Paris in 1992, was the youngest American man to reach this stage at Roland Garros since 19-year-old Michael Chang in 1991.

He grew up watching video tapes of Nadal and even named his cat Rafa after the 19-time Grand Slam champion.

It promised to be the perfect start for the French Open debutant, who had two break points in a nine-minute opening game.

The world number 213 failed to convert as a ruthless Nadal held and then won the following four games on his way to clinching the opening set in 40 minutes.

He eased to the second set in blustery conditions in Paris, before Korda broke early in the third with a combination of fierce backhands.

But Nadal, who is yet to drop a set this tournament, hit back by taking the final six games to win in one hour and 55 minutes.

“I am quite happy about the way that I am playing, and the practices I am feeling every time a little bit better and better,” said Nadal.

Korda said he loved the whole experience of playing his idol, despite his heavy defeat.

“He almost hit an around-the-net forehand and I was kind of begging for it to go in because that would have been the coolest thing ever,” he said. “And then he hit a running forehand winner on me at the lines. I just said to myself, ‘This is awesome’.

“I don’t know if anyone’s ever asked him for an autograph after a match, but that was definitely the coolest moment of my life and one I’ll never forget for sure.”