NEW YORK (AFP) — World No. 1 Aryna Sabalenka overpowered Amanda Anisimova to defend her US Open crown on Saturday, defeating her American rival in straight sets to clinch the fourth Grand Slam title of her career.

Sabalenka ruthlessly attacked Anisimova's shaky service game to complete a 6-3, 7-6 (7/3) victory on the Arthur Ashe Stadium which cements her status at the pinnacle of women's tennis.

The 27-year-old from Belarus had gone into Saturday's final knowing it was her last chance to grab a Grand Slam crown in 2025 after agonising losses in the Australian and French Open finals.

Sabalenka duly atoned for those defeats to end Anisimova's hopes of a remarkable redemption just two months after her traumatic 6-0, 6-0 thrashing by Iga Swiatek in the Wimbledon final.

"It's crazy, all those tough lessons were worth it for this one," said Sabalenka after becoming the first woman to successfully defend the US Open since Serena Williams in 2014.

"I'm speechless right now."

Anisimova had won six of nine previous encounters against Sabalenka, a run which included a victory in the semi-finals at Wimbledon.

But a determined Sabalenka, playing in the seventh Grand Slam title game of her career, brought all her experience to bear as she slammed the door on Anisimova's dream of a maiden Grand Slam title.

"Losing in two finals in a row is great but it's also super hard," Anisimova said. "I think I didn't fight hard enough for my dreams today," revealing that the lighting under the arena's closed roof had made it difficult to serve.

"There was no way of adjusting, because I could not see the ball when I was serving, and that was a huge shock to my system," she said.

Sabalenka clinched victory after once again demonstrating her incredible prowess in tiebreaks — winning her 19th consecutive breaker 7/3 to clinch in one hour and 34 minutes.

Anisimova, meanwhile, was left ruing her inability to make the most of break points at key moments, in sharp contrast to Sabalenka who converted five of her six break point chances.

That imbalance was on display early in the first set, when Anisimova failed to convert three break points openings as Sabalenka took a 2-0 lead.

Yet Anisimova hit back in the third game, lasering a backhand winner into the corner to earn break point before unfurling a rasping forehand winner to break back before holding for 2-2.