Aryna Sabalenka emphatically marched to back-to-back Australian Open titles with a convincing straight-sets win over China's Qinwen Zheng in Saturday's women's singles final.

The defending champion struggled to put the match to bed in the closing stages, missing four match points as Zheng briefly threatened a monumental comeback, but the second seed ultimately ran out a deserved 6-3 6-2 victor over the first-time major finalist.

Sabalenka powered her way to a second Grand Slam singles title without dropping a single set over the past two weeks, while she is also the first women's singles player to win consecutive titles since her fellow Belarusian Victoria Azarenka in 2012 and 2013.

Furthermore, the 25-year-old's Melbourne crowning represented her 14th title on the WTA Tour overall - 12 of which have been won on hard courts - while Zheng, competing in a Grand Slam trophy match for the very first time, was simply overpowered on the day.

"It has been an amazing couple of weeks, it is an unbelievable feeling right now. As always my speech is going to be weird, it's not my superpower, but I'll do my best," Sabalenka said on the court with the trophy in her grasp.

"I want to congratulate Qinwen on an incredible couple of weeks in Australia. I know this feeling. It's really tough to lose in the finals but you are such an incredible player and such a young girl, you are going to be in many more finals and you're going to get it. Congrats to you and your team on an amazing job.

"I never speak about my family in my winning speeches, should I go on, they won't understand me. Hopefully someone will translate! I love you so much, you're my biggest motivation, I'm doing it for you. And thanks for the incredible crowd here, that's what makes this place special."

While Zheng did not face a single seeded opponent en route to Saturday's headline encounter, Sabalenka avenged her US Open final loss to Coco Gauff to set up a showdown with the Chinese 12th seed, who entered the match with more aces than any other women's player at the tournament.

Zheng's resolve eluded her at the start, though, as Sabalenka broke her 21-year-old opponent in her opening service game and fell 40-0 down behind her own serve in the eighth, only to find a resilient streak and force Sabalenka to serve out the opener.

The reigning champion did so to conclude the first set in just 33 minutes, and the writing was on the wall for Zheng after a catastrophic opening service game in the second set, where the 12th seed double-faulted three times, including on break point for Sabalenka.

Serving errors reared their ugly heads for Zheng again in the fifth game, as Sabalenka earned the double break thanks to another two double faults from the first-time finalist, but there was still some fight left in the challenger.

At 40-0 down while Sabalenka was serving for the title, Zheng managed to save all three championship points and also delayed Sabalenka's coronation for a fourth time, but on her fifth opening, the Belarusian found the mark with a blistering cross-court forehand beyond the futile reach of Zheng.

The 25-year-old was down 14 to 19 on the winners count in Saturday's final, but she ended the 76-minute battle with an 84% win rate behind her first serve, while Zheng won just 38% behind her second as she lost to Sabalenka for the second time, having also been thrashed by the Belarusian in last year's US Open quarter-finals.