Ashleigh Barty has returned serve at armchair critics questioning her motives with a ruthless display to march into a second straight US Open women’s doubles final.

Already guaranteed to regain her world No.1 singles ranking after the tournament and eyeing rare back-to-back doubles crowns in New York, Barty and dual Australian Open winner Victoria Azarenka crushed Aliaksandra Sasnovich and Viktoria Kuzmova 6-0 6-1 in the semi-finals on Thursday.

Then Australia’s darling of the court hit back at social media trolls and tennis experts who questioned her decision to compete in doubles at the season’s final major while being a serious singles contender.

“You love that Ash Barty plays doubles (with @vika7 no less)….you love less that she is the No.2 seed and is spending her ‘off’ day winning a 2x (second-round) match that just ended 12-10 in a third set tiebreaker,” Tennis Channel analyst Jon Wertheim tweeted after her fourth-round singles exit.

Barty offered short shrift to the criticism after taking a giant stride towards becoming the first woman since Nathalie Dechy in 2006-07 to successfully defend her US Open doubles title.

“There are a lot of experts out in the world. There are a lot of people who think they know my team and my body and my decision and my thinking,” Barty said.

“But, at the end of the day, it’s my career and I certainly don’t really take notice of that. They’re not people I’m worried about.

“I’m here enjoying my time playing singles and doubles – I don’t do it every week – but the weeks that we do, I think we’ve certainly make the most of it.”

Azarenka, also a former world No.1 but chasing a first grand slam doubles trophy, also leapt to Barty’s defence.

“That’s why they’re called trolls,” the Belarusian said.

Champion last year with Coco Vandeweghe, Barty said it was “really cool” to earn another crack at grand slam glory.

“The best part of this fortnight is Vika and I have played some really good tennis at times and it’s only going to help our singles as well,” she said.

I feel like I’m in a great place off the court and enjoying myself on the court.”

Barty and Azarenka will meet either Elise Mertens and Aryna Sabalenka or Vania King and Caroline Dolehide in Sunday’s final.

It will be Barty’s third doubles final at Flushing Meadows, after she lost the 2013 showpiece with fellow Australian Casey Dellacqua.

Barty, who will reclaim the top singles ranking on Monday from Naomi Osaka, is also poised to become the only player to qualify for this year’s season-ending championships in both disciplines.

Already the first – and to date – only player to seal her singles entry, 23-year-old Barty and Azarenka will also climb into the top eight in the 2019 Race to Shenzhen in doubles if they win the US Open.

-AAP