NEW YORK (AP) — Defending champion Aryna Sabalenka moved into the second round of the U.S. Open on Sunday after weathering a challenging first set in her first match.

The No. 1 player took down Swiss player Rebeka Masarova 7-5, 6-1, but it wasn’t without struggle. Sabalenka went down a break early in the first set, keeping the two neck-and-neck until the defending champion was able to pull away from their 5-5 deadlock.

Sabalenka then dominated the second set, dropping only one game en route to her eventual victory.

“I feel like I didn't start my best in the first games, but then I found my rhythm. Happy with the level I played today,” she said after the win.

She credited the crowd at Arthur Ashe Stadium for helping her make it through that tight first set.

“When I won that set point and you were cheering me up, I had goosebumps while I was sitting,” Sabalenka said on the court. “Your support means a lot to me, and thank you so much.”

The three-time Slam champion has gone through three of this year's four Grand Slams without a title.

“I would love to finish the season with a Grand Slam and world No. 1,” she said Friday. “But I think if this goal is not going to be achieved, I'll still think that this season has been really amazing for me. All of those tough lessons I learned this season only going to make me stronger for the next one.”

She will face Polina Kudermetova in the second round. Sabalenka defeated her in their most recent matchup in Dubai in February.

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