Caroline Wozniacki's painful wait is over after tennis's perennial grand slam bridesmaid finally reigned with a compelling Australian Open final triumph.

In a gripping climax to one of the most memorable women's Opens on record, Wozniacki wore down battered top seed Simona Halep 7-6 (7-2) 3-6 6-4 in two hours and 49 minutes of incredibly intense tennis on Saturday night.

The now Great Dane wept tears of joy after also returning to the top of the rankings - ending a record six-year stint between drinks - with the watershed win at Melbourne Park.

In denying the brave but vanquished Halep her own elusive grand slam breakthrough, Wozniacki not usurped the Romanian as world No.1 but also delivered Denmark its maiden grand slam singles crown.

Wozniacki's stirring victory completed one of sport's great comeback tales after the 27-year-old spiralled to 74th in the world in August of 2016, just 23 months after falling short in her second US Open final.

It's taken Wozniacki 11 years, 43 majors, 256 tournaments, 772 matches and untold hours of toil and tears to shed her tag as tennis's most accomplished talent without a grand slam win.

Herself a two-time grand slam runner-up, on the Paris clay in 2014 and 2017, Halep made a nervy start to the finale.

Playing in sapping heat and humidity, Halep dropped serve with an overcooked backhand in the second game of the match as Wozniacki powered to a 3-0 lead.

But, after looking in control, Wozniacki's first display of tension came with the second seed serving for the opening set at 5-3.

Distracted by an overzealous fan in Rod Laver Arena, Wozniacki urged the chair umpire to intervene.

The rattled Dane promptly dropped serve for the first time, before regaining her cool to dominate the tiebreaker to pocket the opening set in 50 minutes.

Halep, who carried an ankle injury throughout her gruelling two-week campaign, called for the tournament physio while leading 3-2 in the second set.

The hobbling top seed resumed after having her pulse and blood pressure checked and bravely snatched the second set after reeling off three straight games to set up a thrilling conclusion.

But it was Wozniacki who finally prevailed, emerging from a 10-minute break allowed under the Open's heat rule to claim the rollercoaster third set featuring seven services breaks.