SHANGHAI, China (AFP) — Second seed Alexander Zverev scraped through to the Last 16 of the Shanghai Masters, winning two tiebreaks against the Netherlands’ Tallon Griekspoor in an ill-tempered match that ended 7-6 (8/6), 2-6, 7-6 (7/5).

Novak Djokovic, meanwhile, powered through the third round, steamrolling Italian Flavio Cobolli 6-1, 6-2 in just over an hour.

Zverev’s first set against 40th-ranked Griekspoor was overshadowed by the German’s prolonged, expletive-laden exchange with the umpire when he disagreed with a call.

“I cannot be bothered to go to China in October, for you to screw up. I cannot, this is not possible,” Zverev ranted before tossing his racket across the court.

The world No. 3 claimed the first set, but proceeded to fall apart in the second, with the Dutchman breaking him in the first, third and fifth game.

Zverev squandered an early lead in the third set tiebreak but an unforced error on Griekspoor’s part saw him crowned winner.

“Every time I play him it’s the most difficult match,” said Zverev, saying there had been “not much difference” between them.

In contrast, Djokovic, a four-time Shanghai champion, completely dominated 30th-ranked Cobolli, breaking him in the second and sixth games of the first set.

“I can’t complain about anything in the game, I was able to play aggressively,” Djokovic said.

“I’m glad to be progressing through a tournament that has meant a lot to me in my career.”

Fans waved Serbian flags and screamed in delight when the former world No. 1 wrote part of his Chinese character name on a camera lens at the end of the match.

Djokovic will next play Russian Roman Safiullin, who upset Frances Tiafoe in three tight sets.

The end of that match also saw the American swear repeatedly at the umpire.

The Last 16 has finally fallen into place after days of schedule disruption due to rain.

Ben Shelton dispatched Spain’s Roberto Carballes Baena 6-3, 6-4 to set up a Shanghai rematch with world No. 1 Jannik Sinner of Italy.

The American knocked Sinner out of the tournament at the same stage last year.

“(I have) great memories from that match last year, I probably watched the tape of that a couple times so far this year... I’m really looking forward to it, that will be fun,” Shelton said.