Quarterfinal spots were on the line in Day 7 at the 2021 Australian Open, and several big names were able to keep their championship hopes alive.
Novak Djokovic and Simona Halep advanced despite difficult challenges Sunday, while Serena Williams needed three sets to continue her quest for her 24th Grand Slam title.
The day also featured some surprises as Dominic Thiem was eliminated while unseeded players Aslan Karatsev and Su-Wei Hsieh kept their dream runs alive.
The stakes continue to rise with each round at Melbourne Park.
No. 1 Novak Djokovic def. No. 14 Milos Raonic; 7-6(4), 4-6, 6-1, 6-4
No. 18 Grigor Dimitrov def. No. 3 Dominic Thiem; 6-4, 6-4, 6-0
No. 6 Alexander Zverev def. No. 23 Dusan Lajovic; 6-4, 7-6(5), 6-3
Aslan Karatsev def. No. 20 Felix Auger-Aliassime; 3-6, 1-6, 6-3, 6-3, 6-4
No. 2 Simona Halep def. No. 15 Iga Swiatek; 3-6, 6-1, 6-4
No. 3 Naomi Osaka def. No. 14 Garbine Muguruza; 4-6, 6-4, 7-5
No. 10 Serena Williams def. No. 7 Aryna Sabalenka; 6-4, 2-6, 6-4
Su-Wei Hsieh def. No. 19 Marketa Vondrousova; 6-4, 6-2
Full results and stats available at AusOpen.com.
One of the main stories entering the day was the health of Novak Djokovic, who suffered an injury in Round 3 and was uncertain if he would return in time for Sunday's match.
"I know it's a tear, definitely, of the muscle. So I don't know if I'll manage to recover from that in less than two days," he told reporters. "I don't know. I don't know. I don't know if I'm gonna step out on to the court or not."
The No. 1 seed gutted it out against Milos Raonic, overcoming 26 aces from his opponent to win in four sets.
Djokovic was broken just once in the match, winning 74 percent of all service points to escape with the win, although the injury was still a significant concern:
He will hope to recover in time to face Alexander Zverev in the quarterfinals after the German cruised to victory against Dusan Lajovic.
Grigor Dimitrov had an easier time than expected against No. 3 Dominic Thiem, with Thiem also noting an injury after the match.
"Some little physical issues. I don't want to talk closer than them," he said Sunday. "I don't want to find excuses. The thing is also, I'm not a machine. I'd like to be."
Thiem finished with 41 unforced errors in the three sets with just 25 winners, also finding little success on his second serve. Dimitrov took advantage and is onto the quarterfinal for his fourth time at this event.
His next match will be against Aslan Karatsev, who had never even reached the main draw of a Grand Slam before this event. He doesn't appear to be slowing down, coming back from two sets down against Felix Auger-Aliassime to earn a thrilling five-set victory.
There was plenty of drama in the women's draw as well with Simona Halep, Serena Williams and Naomi Osaki all going to three sets in their wins.
Halep had a slow start against Iga Swiatek, tallying 10 unforced errors in her first set before combining for just seven in the final two sets. The turnaround led to an impressive win and an exciting quarterfinal match against Williams:
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Serena Williams is 9-2 vs Simona Halep. Last time they played in Melbourne, Halep pushed Serena the distance. Last time they played full stop, Halep delivered one of the most jawdroppingly flawless performances imaginable to beat Serena 2&2 in the Wimbledon final.
Williams had her own challenges in Round 4 against No. 7 Aryna Sabalenka, dropping a set for the first time all tournament. The American was still able to pull out the win thanks to her aggressiveness at the net, winning 13 of 15 points.
Osaka is one step closer to her second title in Australia after her narrow win over Garbine Muguruza, but the red-hot Su-Wei Hsieh could remain a challenge after her second straight-set win over a seeded opponent this tournament.
Regardless of the numbers next to the names, there are no easy matches at this stage of the Grand Slam.
The tournament continues Monday with Rafael Nadal and Ashleigh Barty highlighting the remaining Round 4 action.