New York, United States, 4 September 2019 | Darren Walton (AAP)

Ash Barty is two wins from becoming the first woman in 12 years to win back-to-back US Open doubles titles after reaching the semifinals with Victoria Azarenka.

Australia’s tennis superstar on Tuesday took a giant stride towards notching another major milestone in her incredible 2019 season.

She and Azarenka powered into the US Open last four with a 2-6 7-5 6-1 comeback win over top seeds Timea Babos and Kristina Mladenovic.

Barty teamed with American Coco Vandeweghe to topple Babos and Mladenovic in last year’s final at Flushing Meadows.

That breakthrough earned Barty her maiden Grand Slam title after she’d lost all four major finals in Melbourne, Paris, London and New York with fellow Australian Casey Dellacqua.

Frenchwoman Nathalie Dechy was the last player to achieve the feat of back-to-back US Open doubles titles, doing so in 2006 and 2007 with Russians Vera Zvonareva and Dinara Safina.

Set to regain her world No.1 singles ranking next week, 23-year-old Barty and Azarenka will play either Viktoria Kuzmova and Aliaksandra Sasnovich or third seeds Gabriela Dabrowski and Yifan Xu in the semifinals.

 

Ash Barty (L) and Victoria Azarenka celebrate their US Open quarterfinal victory over No.1 seeds Timea Babos and Kristina Mladenovic (Getty Images)

Ash Barty (L) and Victoria Azarenka celebrate their US Open quarterfinal victory over No.1 seeds Timea Babos and Kristina Mladenovic (Getty Images)