Bianca Andreescu stuns Serena Williams in historic US Open win

Bianca Andreescu has withstood a remarkable Serena Williams fightback to win her maiden grand slam title after a dramatic US Open final.

The Canadian 15th seed’s 6-3 7-5 victory was by no means as straightforward as the scoreline suggests.

Andreescu looked to be cantering towards the title after having a chance to serve for the championship at 5-1 up in the second.

However, the 19-year-old's wobbles and Williams' supreme experience set up a tense end to the second set, before Andreescu finally prevailed.

The amazing win for the underdog once again denied Williams what could have been a record-equalling 24 grand slam singles title - a mark held by Australia's Margaret Court.

Bianca Andreescu is Canada's first ever grand slam winner. Pic: Getty

Andreescu's extraordinary maiden grand slam title means she is the first Canadian to win a grand slam singles title.

The 19-year-old is also the first person born in the 2000s to win a major trophy.

The incredible performance left fans in a frenzy on social media.

Ranked 178th in the world at the start of year, Andreescu overcame a dramatic second-set collapse to deny Williams a record-equalling 24th grand slam singles crown.

Title success on her main-draw debut at Flushing Meadows marked the equal-fastest journey to grand slam glory in tennis history, matching Monica Seles' feat in winning the 1990 French Open in only her fourth major.

The fearless 19-year-old is also the first Canadian to win a singles grand slam and first teenager to hoist the US Open trophy since Maria Sharapova in 2006.

Not even born when Williams won the first of six titles in New York in 1999, Andreescu defied the doubters with an extraordinary baseline barrage as Williams once again crumbled under pressure trying to match Margaret Court's 24 singles slams.

It was the fourth consecutive grand slam final defeat for the American since returning from maternity leave after the birth of her daughter Olympia in September 2017.

But this one will likely hurt most with Williams injury free and finally back to full fitness, adamant pre-match she'd never been better prepared to return to the grand slam winners' circle.

Alas, after also falling to Naomi Osaka in last year's final and to Angelique Kerber and Simona Halep in the past two Wimbledon deciders, time may be running out for Williams - who turns 38 this month - to catch Court.

The near-19-year age gap between the two finalists in New York was the largest in open-era tennis, but it was the rookie who rose to the occasion.

Williams started the match with an ace, only to gift the Canadian a break in the opening game with five unforced errors, including successive double-faults.

Serena Williams staged an epic second set comeback. Pic: Getty

It was the only break she needed as Andreescu, rock solid on her own serve and with a potent mix of power and spin from the baseline, controlled the first set.

Williams had to fight off five break points in an epic 11-minute seventh game to hold for 3-4.

But another double-fault on set point in the ninth game handed Andreescu a one-set lead after 42 minutes.

Williams was staring down the barrel trailing 5-1 and match point in the second set before nerves took hold of her young rival.

Andreescu lost four games straight to allow Williams back on level terms at 5-5.

But, not to be denied, the teenage sensation finally prevailed on her third match point with a scorching forehand return winner after one hour and 40 minutes to improve her perfect record over top-10 rivals in 2019 to a remarkable eight from eight.

Andreescu's third title of the year will lift her to world No.5 when the rankings are updated on Monday.

With AAP