In a battle between former World No.1 players, No.22 seed Karolina Pliskova overcame No.26 Victoria Azarenka 7-5, 6-7(5), 6-2 to reach the US Open quarterfinals.

Pliskova, the US Open runner-up to Angelique Kerber in 2016, took a hair over three hours to outlast the three-time finalist Azarenka (2012, 2013 and 2020).

It was the first meeting between the two tour veterans since 2019. Pliskova now leads their head-to-head 5-4.

Pliskova will next face No.6 seed Aryna Sabalenka, who came back from a set down to defeat No.19 Danielle Collins 3-6, 6-3, 6-2 to advance to her second US Open quarterfinal.

The win was Sabalenka's second comeback of this event. In the second round, she saved match points against Kaia Kanepi.

Read more: How Pegula, Swiatek can keep the momentum going at the US Open

Here's how Pliskova and Sabalenka can excel as the draw progresses:

Karolina Pliskova

Trust the conditions

Azarenka has a strong record at the US Open, but Pliskova is becoming a top performer in New York as well. She had never made it beyond the third round at a Grand Slam coming into the 2016, but she raced through to that final and unlocked a good amount of success at the US Open.

From 2016 to the present, Pliskova has reached the US Open quarterfinals or better five times, with a 26-6 win-loss. The court speed and atmosphere suit the big hitter, and she can use her comfort at this site to her best advantage.

Steady as she goes

Pliskova battled through her hard-fought match with Azarenka by keeping her unforced error count relatively low. On Monday night, Pliskova had 53 winners but only 36 unforced errors. Azarenka's differential was still positive, but she had only nine more winners than unforced errors.

Pliskova has been staying steady and not making many mistakes considering how fiery her game has remained. That paid dividends in the first set, where she came back from a break down and saved two set points. If she continues to be safe when she needs to be before picking her moments to strike, look out.

But, of course, the serve

Pliskova didn't hold the "Ace Queen" moniker for so many years for no reason. Even with improved defense and more margin, Pliskova is still going to achieve the most when her first serve is clicking.

After falling just short in the second-set tiebreak, Pliskova regrouped for the third behind her first delivery. In the final set, the Czech won 23 of her 27 first-serve points (85 percent) and never faced a break point.

After two grueling sets, the first serve was a major factor in helping Pliskova sail through the third. That weapon will continue to be a determining factor as she tries to advance further.

Aryna Sabalenka

Keep playing with house money

Sabalenka nearly had her plane ticket booked out of New York in the second round. Instead, the 2021 semifinalist manufactured a spirited comeback against Kaia Kanepi, saving two match points and coming back from a set and 5-1 down to win 2-6, 7-6(8), 6-4. 

Since then, Sabalenka has played freely. She lost only two games to Clara Burel in the third round. Against Collins, Sabalenka found herself against an opponent who was happy to trade power for power and the American was the more successful for a set and a half. Collins ran through the opening set with 12 winners to eight unforced errors, outpacing Sabalenka's eight winners. 

In the second set, Sabalenka dug in. She held serve through a 22-point game to lead 4-3. As Collins struggled to find her first-set range, Sabalenka stayed steady. She lost just two more games in the match. 

Just keep breaking

To her credit, Sabalenka has been open about her serving struggles this year. In New York she has struck 25 double faults to 16 aces. Her ability to put the mistakes behind her has made her a dangerous and unpredictable opponent. At the start of the season the double faults would rattle her. Now, if she loses a game she simply steels herself to break back. 

In New York she has been broken 13 times. But she has broken her opponent's serve 23 times. 

Be ready to work

Sabalenka needed 2 hours and 29 minutes to get past Collins. She also needed a medical timeout in the second set to address a left leg issue. Recovery will be key for Sabalenka ahead of her meeting fifth meeting with Pliskova. Three of their four prior meetings have gone three sets, and she has not beaten the Czech since 2018. The two met twice last year, with Pliskova edging Sabalenka in the semifinals of both Wimbledon and Montreal. 

Pliskova has shown great physicality throughout the US Open, highlighted by her three-set wins against Bencic and Azarenka. Sabalenka will need to be ready for another tough effort.