Alexander Zverev fought off a cold and the blistering power of Nikoloz Basilashvili at the Shanghai Masters on Wednesday, calling the Georgian "the hardest-hitting player I have ever played against".
The young German star and fourth seed joins Novak Djokovic and Juan Martin del Potro in the last 16 after defeating the on-form Basilashvili 7-5, 6-4.
The 21-year-old Zverev suffered an early exit last week at the China Open in Beijing, where Basilashvili beat Del Potro for just his second ATP title on Sunday.
Zverev, who departed the Beijing hard courts by smashing his racquet, kept his cool this time to beat Basilashvili in 92 cagey minutes.
WATCH: There was a surprise in store for a ball boy during Alexander Zverev's match against Nikoloz Basilashvili at the Shanghai Masters. ??
— Sky Sports Tennis ? (@SkySportsTennis) October 10, 2018
? https://t.co/8dpnn2jXFi pic.twitter.com/BFfcMhsnbN
Zverev, who said that he had a sore throat and blocked nose, will play Australia's world-ranked 33 Alex de Minaur next.
De Minaur, 19, defeated France's Benoit Paire 6-4, 6-3 to enhance his growing reputation.
Zverev said that Basilashvili, who is up to a career-high ranking of 23, "knows how to play, definitely".
"Probably the hardest-hitting player I have ever played against," said Zverev.
"I mean, I played all right. I played a solid match. I did everything that I needed to win."
Alexander Zverev hangs tough to prevail over @ChinaOpen champion Nikoloz Basilashvili 7-5, 6-4.
— ATP World Tour (@ATPWorldTour) October 10, 2018
How far will the No. 4 seed go this week?#ATPMasters1000 pic.twitter.com/PESlVLf6Q2
The 30-year-old Argentine Del Potro outlasted stubborn Frenchman Richard Gasquet to stay in the hunt at the Masters 1000 event.
Del Potro, who similarly suffered with cold and flu in the China Open final, was broken on his service to immediately go a game down.
But under pressure from the 32-year-old Gasquet, the third seed belatedly found his rhythm, coming from behind in both sets to win 7-5, 7-6 (9/7).
Del Potro, who sealed the match with an ace and a swing of his fist, will face 13th seed Borna Coric of Croatia next.
Number two seed Djokovic nailed his place in the last 16 on Tuesday with a convincing victory over Jeremy Chardy.
Zverev defeats Basilashvili in straight sets 7-5, 6-4.@delpotrojuan vs @richardgasquet1 up next.
— Tennis Channel (@TennisChannel) October 10, 2018
Stream Live→ https://t.co/yAD7oWktvH #RolexShMasters pic.twitter.com/81CEBvA8Ah
Reigning Shanghai champion and top seed Roger Federer begins his defence later Wednesday against Russia's Daniil Medvedev, who is fresh from winning the Japan open.