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As it turned out for Serena Williams and Aryna Sabalenka on Friday in Melbourne, it's not how you win — it's just that you do.

Seven-time AO champion Williams needed to battle past a determined effort from Russian teenager Anastasia Potapova, 7-6(5), 6-2, saving two set points in the first set and overcoming 31 unforced errors to set an enticing fourth-round meeting against the Belarusian No.1.

Earlier in the day on Rod Laver Arena, Sabalenka eased to a 6-3, 6-1 win over Williams' compatriot Ann Li, improving her record to 18-1 since October. 

The two have never played.

"It's a big challenge, but it's a tough one, but I'm going to do everything I can to prepare myself for that match, like mentally be ready to get this win," Sabalenka told reporters after her 60-minute victory over the in-form World No.69, ending the latter's six-match winning streak.

"She's a great player, and it's always a big challenge to play against these kind of players. But I'm going to do everything I can to get this win. We're all here for the wins and I'm going to do everything."

Sabalenka will bid for her first career Grand Slam quarterfinal appearance, having last reached the round of 16 at the 2018 US Open. That year, she was the only player to take a set off of eventual champion Naomi Osaka. 

"The first time [I saw her play], I think... I was around 13 years old. I think I said, 'I want to hit even stronger than her (laughing). I don't know if it was, was it smart or not, but [at] that point, I was thinking like, 'Wow, she's really powerful. I want to be like powerful, too, and I want to dominate on the tour the same like she do.'"

- Aryna Sabalenka on Serena Williams

Having won just three games against Williams in their last meeting, in the first round in Melbourne a year ago, the Russian 19-year-old showed just how much she's improved since then as she went toe-to-toe with the 23-time Grand Slam champion over the course of an hour and 37 minutes. 

Twice breaking Williams' vaunted serve in the first set, Potapova's first-strike baseline tennis earned her leads of 4-2 and 5-3, which included two set points on her serve in the ninth game. However, the World No.101's own delivery faltered once there, as she served six double faults in all to allow the American back into the match. 

“I just was not striking in that first set. I was making errors, I was slow," Williams told ESPN's Rennae Stubbs after the match. "At one point, i just started playing defense because it was the only thing I could do.”

Later, she added: "It was good to get through that match. The first set was extremely tight. I was a little tight, but it worked out. I was able to play a little more free in the second set."

In all, the teenager held a trio of leads from then on, but advantages of 3-1 and 5-3 in the tiebreak, and 2-0 in the second set were erased by Williams' runs of five straight points and six straight games. 

Williams has not faced a Top 10 player in an official match since beating Elina Svitolina in the semifinals of the 2019 US Open. Sabalenka checks in at World No.7.

"She hits very hard. She has a big, big power game," the American assessed. "She's a big girl. Strong like myself. I think it will be a really good match."