Belarusian Aryna Sabalenka beat American sixth seed Jessica Pegula 7-5, 7-5 in the U.S. Open women's singles final on Saturday.

Sabalenka blocked out the wild cheers for the home hope at Arthur Ashe Stadium to break Pegula in the final game and win her first title at Flushing Meadows.

A year after coming up short in the final, the second seed fought back from a break down in both sets to claim victory and fell to the court in her moment of triumph.

30-year-old Pegula has waited a long time to reach her first major final but could not match her opponent's raw power despite the noisy backing of the New York crowd.

The roof on Arthur Ashe Stadium was closed due to heavy rain and the players traded breaks twice as they settled into the stormy affair in front of a celebrity-packed house.

Sabalenka held her serve through a four-deuce 11th game and fought through a spine-tingling 12th, mixing precision at the net with her usual power from the baseline before breaking her opponent on the fifth set point.

Pegula struggled with her rackets throughout the match, complaining to her coaches as she seemed unable to find the right tension on her strings, and it looked as though she would not put up a fight in the second set when Sabalenka went 3-0 up.

But the American found another level and brought the fans to their feet when she won the next five games in a furious fight back.

Sabalenka levelled when she sent over a forehand winner that just kissed the line on break point in the 10th game and sought to bring a swift end to the contest, holding serve and then applying pressure from the baseline in the final game.

The tears flowed immediately for Sabalenka as she claimed her third Grand Slam title after winning the Australian Open twice, and she high-fived fans as she ran up the stands to share a joyful celebration with her team.