Americans Jessica Pegula and Madison Keys have turned up the heat on the Australian Open 2022 field, following respective upsets of top-eight seeds for quarterfinal berths.
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The 21st seed Pegula made it back-to-back appearances in the last eight at Melbourne Park with a 7-6(0) 6-3 triumph over fifth seed Maria Sakkari, while former semifinalist Keys made short work of Sydney champion Paula Badosa.
On a searing Sunday afternoon in which the mercury topped 32 degrees Celsius, Pegula matched her best run at a major, which came on the same courts last year, when she picked off upsets over the likes of Victoria Azarenka and Elina Svitolina.
Her first victory in three attempts against the Greek was her eighth over a top-10 rival, all of which had come since her breakout run at Melbourne Park in 2021.
"That definitely was the best match I've played this year, you know, this tournament for sure," Pegula said. "I'm glad I was able to bring it today and keep my stats pretty well.
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"I think it showed… I had a lot of really tough matches. I honestly was just really excited to play today."
The 27-year-old had made an impressive 17 out of 21 returns as Sakkari hung by a thread, a point from conceding the opening set on serve.
The Greek survived that and had made steady inroads from 3-5 down as her improving consistency slowly enabled her to sway momentum.
Sakkari, who reached her first two Grand Slam semifinals at Roland Garros and Flushing Meadows last year, had worked overtime to edge her nose in front but after Pegula forced the tiebreak, it was one-way traffic.
The 27-year-old was exceptionally solid against an increasingly agitated opponent and a fourth ace sealed the opener after 56 minutes.
Pegula was wearing her opponent down as she landed the mortal blow with a break at 3-1 and never looked back.
"I thought I returned really well. I really, from the start, wanted to put a lot of pressure on her serve," the 21st seed said. "I think that worked really well.
"I know I'm not going to out-grind her. She's an unbelievable athlete and way better at that than me so, I knew I had to take my chances, but you know, also be patient and play as smart as I could. Luckily I was able to do that."
A devastated Keys was forced to watch the Australian Open from home last year after she tested positive to Covid-19 ahead of her scheduled flight to Melbourne.
On Sunday, the 26-year-old former world No.7 continued to make the most of her return when she trounced eighth seed Badosa 6-3 6-1 to reach the quarterfinals at Melbourne Park for the first time since 2018.
An Australian Open semifinalist seven years ago, Keys' penetration from the back of court was damaging from the off as she raced to a 4-1 lead against one of the form women leading in.
Badosa had added her name to the decorated honour roll in Sydney to start 2022 but had not come up against such a relentlessly heavy ball-striker in this campaign.
Keys was all but unplayable on serve as she held with an ace for 5-2 and finished the set two games later with a love hold, having dropped just three points on her first serve, and with a hefty 16 winners.
Badosa had done well to stay within reach as she saved 10 of her first 11 break points faced, but was broken immediately to open the second set.
There was a growing sense of urgency for the Spaniard and while she managed to secure her first break to level, she was again under the pump.
Such was the pressure from Keys', her opponent threw in consecutive double faults and looked under duress at the change of ends as the mercury first jumped above 30 degrees Celsius.
A 10th double fault soon had the eighth seed staring down match point and a yell of "c'mon" from Keys reverberated as she sealed the result at the 71-minute mark.
"It was absolutely amazing. I'm so happy to be back. I was so sad to miss last year," Keys said. "I think I served pretty well and I think I returned really well so I think I just kind of, off of the first ball, had the advantage on a lot of the points and then was able to dictate.
"I knew that I was going to have to take my chances and go for it because if I gave her an inch she was going to take it."