SHANGHAI, China (AFP) — Shanghai Masters third seed Holger Rune crashed out of the tournament in straight sets on Friday, the highest-profile of several top-20 players to be knocked out that day.

World No. 5 Rune never found his rhythm as he fell 6-0, 6-2 to 22-year-old American Brandon Nakashima, ranked 122nd in the world.

Despite the crowd enthusiastically cheering the Dane on, Nakashima made short work of Rune, defeating him in an hour and nine minutes.

"I had to play my best tennis to pull through," Nakashima said after the match.

"(Rune) is a player who has been at the top of the game for a while so I know against him it's going to be tough every time."

World No. 10 Alexander Zverev is also out after being overpowered by 50th-ranked Roman Safiullin.

It was sweet revenge for the Russian, who missed out on a first tour-level title in late September when Zverev came back from a set down to beat him in the Chengdu Open.

This time the visibly frustrated German couldn't recover in the second set, ultimately conceding 6-3, 6-1.

"I would say (I had) a very good performance today," said Safiullin after the match, adding he had studied his "many mistakes" in the Chengdu final to avoid them reoccurring.

There was also an upset for Alex de Minaur, who lost 6-3, 7-5 to Hungarian Fabian Marozsan, who is ranked 91st to the Australian's 11th.

It was Marozsan's second high-profile knock-out of the year — in May he inflicted a shock defeat on Carlos Alcaraz at the Italian Open.

Hungary claimed another top-20 scalp later in the afternoon, when 31-year-old Marton Fucsovics beat the world No. 15, Canadian Felix Auger-Aliassime.

Fucsovics, ranked 57th, ripped off his shirt and roared in jubilation after a tightly fought match that lasted almost three-and-a-half hours and ended 7-6 (7/3), 4-6, 6-3.