World number one Aryna Sabalenka fought off host Amanda Anisimova to defend her US Open title and finally win her first Grand Slam trophy of the year.

Sabalenka held her own to win 6-3, 7-6 (7-3) in a battle between the two most powerful women's players, the BBC reports.

The Belarusian player fell to her knees, overcome with emotion, after securing victory in a year in which she lost two Grand Slam finals.

The victory did not come without some tension, however.

Defending champion Sabalenka fell behind at 5-4 but recovered to dominate the tiebreak and seal victory on her third match point.

The 27-year-old has once again been the most dominant player on the WTA Tour this season, but questions have been raised about her emotional composure in the latter stages of the Grand Slams.

Sabalenka answered her critics in the final major of the season with a largely confident performance to win her fourth Grand Slam singles title.

Instead, American No. 8 Anisimova paid the price for failing to maintain a consistent level.

The 24-year-old improved from her first Grand Slam final - when she was defeated 6-0, 6-0 by Poland's Juga Švěntek at Wimbledon in July - but was left disappointed and broke down in tears after the defeat.

Experience proves key for Sabalenka

The relief Sabalenka showed after securing the win was borne out by her setbacks earlier this year.

At the Australian Open, the two-time champion was unable to cope with the destructive power of Madison Keys, then lost to Coco Gauff at Roland Garros after committing 70 unforced errors.

Sabalenka had crashed out earlier at Wimbledon, failing to cope with Anisimova's gritty play in the semifinals.

This time, after some dramatic early moments, Sabalenka was focused and playing tactically to avenge her defeat at the All England Club eight weeks ago.

"After two finals where I completely lost control of my emotions, I didn't want to let that happen again," Sabalenka told ESPN.

"There were moments when I was close to giving up, but I kept my cool."

Sabalenka's plan was to pick up Anisimova's pace and force her opponent into mistakes.

Anisimova's experience against Swiatek was harrowing, her nerves too stiff to change tactics in the face of her biggest loss in over a century.

Going through the ordeal made her stronger, but there were still visible signs of tension throughout the gripping final in New York.

But the hesitation was too great, and ultimately the cause of another emotional Grand Slam loss.

The ordeal made her stronger, but there were still visible signs of tension during the thrilling final in New York.

"It's been a great summer. Losing two finals in a row is great, but it's also very tough," Anisimova said.

"I didn't fight hard enough for my dreams today."

Anisimova plays without frills – with all her strength and without finesse, and tried to use this to throw Sabalenka off the court.

But the hesitation was too much and ultimately proved to be the cause of another emotional Grand Slam loss.

Anisimova started strong, hitting powerful shots from the baseline, looking to play on the sidelines.

That created three break points in the first game before Sabalenka recovered, held serve and broke for 2-0, but Anisimova's better hitting allowed her to turn the score around and take a 3-2 lead.

However, nerves returned when she found herself in front.

Her shots became more erratic as she failed to consolidate her lead, before making a shocking serve with two double faults for 5-3.

Sabalenka, who is also prone to fluctuations in her form, remained more stable and took the lead.

While the crowd continued to cheer her on, Anisimova looked irritated as she struggled to serve her first few games of the second set.

The tension was palpable when she fell behind 2-1. Anisimova first hit the ball high in the air before covering her face with a towel.

The mood among the 25,000 fans dipped, but that changed when Anisimova broke to force a tiebreak.

Sabalenka's record in tiebreaks this year has been impressive, and her confidence showed as she built a commanding lead before winning her 19th consecutive break.

"I know how painful these finals are," Sabalenka said. "But after these tough losses, you enjoy success more." I BGNES