CHARLESTON, SC, USA -- No.3 seed Aryna Sabalenka of Belarus evaded an upset in the second round of the Volvo Car Open on Wednesday, coming back from a set down to overcome Ukrainian qualifier Kateryna Kozlova, 3-6, 6-3, 6-3.

"I just looked at my coach when I was 0-2 down [in the second set], and he just said 'Look at your arm,'" Sabalenka told the press, after her win. "There is a tiger.  It means like keep fighting, like forget about everything else, just fight for each point. That's what I did. There is my key."

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World No.10 Sabalenka had won their lone previous meeting in three sets, in the Tashkent quarterfinals in 2017, and this match also went the distance before the top-ranked Belarusian prevailed over the World No.99 in just under two hours of play.

In her debut match at Charleston, Sabalenka had 25 winners, but also 37 unforced errors, while Kozlova had 22 of each. However, nearly half of Sabalenka's unforced errors came in the first set, and the Belarusian was able to pull through in the final two sets with relatively more precise power play.

Sabalenka also had 11 double faults, which "is not what I expect," she admitted. "In the practice I serve like really well. I just need to find this feeling in the matches because I really have [a] good serve, and this is just like -- I just need to bring it on the match court."

Sabalenka will play unseeded Monica Puig of Puerto Rico in the round of 16. 2016 Olympic champion Puig pulled off a second-round upset by beating No.13 seed Sofia Kenin of the United States, 6-4, 6-4.

"I never played against [Puig], but, again, she's a good player, like everyone here is a good player," said Sabalenka.  "I don't really have expectations.  I just will go out there and fight for each point from the beginning of the match -- not from 2-0 down."

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The drop shot flummoxed Sabalenka early, as Kozlova deployed that shot to obtain the first break of the match at 1-1. Kozlova kept grinding through the early stages of the opening set, fending off break point to lead 3-1, then breaking Sabalenka at love to obtain a second break and a commanding 4-1 lead.

Down 5-2, Sabalenka gave Kozlova a taste of her own medicine, returning a drop shot with a drop shot winner of her own to garner one of those breaks back. But the Belarusian was unable to use her power game to maintain that momentum, firing unforced errors at will and handing over another break to Kozlova, and with that, the one-set lead.

Kozlova used tremendous down-the-line backhands to obtain a quick break and a 2-0 lead in the second set, as she continued to control the match. However, a crucial break came for Sabalenka in the following game, and the match began to turn after the Belarusian got back on serve at 2-1.

Sabalenka started to find the range on her rocketing groundstrokes and she cut down on her mistakes, and was rewarded by breaking for a 3-2 lead with a stirring forehand winner. The 3rd seed consolidated for 4-2, saving a break point in the process, and used strong backhands to power her way to 5-3.

Serving to stay in the set in that game, Kozlova lost control of her groundstrokes, spraying errors to set up triple set point for Sabalenka. On her first opportunity, Sabalenka pummelled a forehand service return winner, breaking at love to level the match at one set apiece.

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After an early exchange of breaks, Sabalenka clinched a crucial 3-1 lead after backhand errors flowed off the racquet of Kozlova. The Belarusian saved a break point to hold for 4-1, before using overpowering service returns to attain a second break and build a 5-1 lead.

Kozlova took advantage of forehand errors from Sabalenka to notch one break back and pull to 5-3, but Sabalenka would not waste a second chance to serve out the match, as her overwhelming groundstroke play pulled her over the finish line and a spot in the third round.