Grigor Dimitrov has booked an Australian Open quarter-final meeting with unheralded Russian qualifier Aslan Karatsev after engineering an upset win over Dominic Thiem.
Thiem, the Austrian world No 3, made his shock fourth-round exit in straight sets on Sunday, a year after he pushed Novak Djokovic to five sets in the final of the 2020 tournament.
Dimitrov hustled to a surprise two-set lead over a listless-looking Thiem and cruised through the final set in 21 minutes to win 6-4, 6-4, 6-0.
“Throughout every season you have one of those matches where you just keep the ball rolling and I think today was just one of those days where I was entirely trying to focus on what I was doing,” the Bulgarian 18th seed said. “I think he might have actually struggled with something but I want to give myself credit.”
Thiem had come off a brilliant five-setter against Nick Kyrgios, against whom he fought his way back from two sets down to secure a spot in the fourth round.
He snared an early break against Dimitrov before the Bulgarian responded by breaking Thiem twice to claim the first set. The second was a similar affair, with Thiem again drawing the first break and an early lead before dropping two of his own service games as Dimitrov took control.
He will face an unfamiliar last-eight opponent in Karatsev, who continued his excellent run on his grand slam debut with a 3-6, 1-6, 6-3, 6-3, 6-4 win over 20th seed Felix Auger Aliassime.
Karatsev had not dropped a set in his previous three rounds, including a win over eighth seed Diego Schwartzman, but lost the first two against the Canadian on Sunday at Margaret Court Arena as he struggled with unforced errors.
The 27-year-old world No 114 took a bathroom break after losing the second set and returned a different player, going for broke and keeping a lid on his errors to win three consecutive sets and claim victory in three and a half hours.
In doing so, he became the first male since Alex Radulescu at Wimbledon in 1996 to reach a grand slam quarter-final on their debut. He is also the lowest-ranked man to reach the Australian Open’s last eight since 114th-ranked Patrick McEnroe in 1991 and the first qualifier to advance this far since Bernard Tomic at Wimbledon in 2011.
“It was really difficult in the beginning to play with him. He’s a really good player and was playing really fast and it took me two sets to find my rhythm,” Karatsev said.
“I put everything into this match and I’m really happy. I’ll be ready for everyone.”
Earlier, Serena Williams survived a tough fourth-round encounter with world No 7 Belarusian Aryna Sabalenka to continue in her quest for a record-equalling 24th grand slam singles crown.
The 39-year-old American, 17 years older than her rival, was up 4-1 in the third set but had withstand a fierce fightback from Sabalenka to reign 6-4, 2-6, 6-4 after two hours and nine minutes. Williams will play the winner of Sunday night’s clash between second seed Simona Halep and 19-year-old Pole Iga Swiatek, the reigning French Open champion.
US Open winner Naomi Osaka fought off two match points against 2020 runner-up Garbine Muguruza to pull off a 4-6, 6-4, 7-5 comeback victory and quarter-final tie with Su-Wei Hsieh of Chinese Taipei.