'What the hell': Ash Barty under fire after shock loss at US Open

Ash Barty’s preparation for her fourth round US Open clash has been called into question after a shock loss to China’s Qiang Wang.

The Aussie World No.2 crashed out of the singles in an extraordinary 6-2, 6-4 loss on Sunday.

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As she stuttered to the stunning defeat, some questioned whether her preparation might have let her down.

Sports Illustrated writer Jon Wertheim questioned the wisdom of Barty playing doubles for two and a half hours on Saturday while her opponent was resting up.

Barty and Victoria Azarenka eventually won their doubles clash 12-10 in a third set tiebreaker, but fans questioned whether she would have been better served resting.

However some pointed out that Barty would have been practicing if she wasn’t playing doubles anyway.

Barty reflects on tremendous year

But rather than dwell, a philosophical Barty preferred to reflect on a watershed grand slam season, highlighted by her magical French Open triumph in June.

"It's been incredible. Yeah, I mean, it's a tough day at the office today, but it's been a year where we've hit our goals. Obviously I would have loved to have kept going here in singles, but we've got an opportunity to do that in doubles," Barty said.

"Knowing what it was like last year to be able to lift the trophy in doubles was really cool. To be able to have another opportunity to do that now, still being able to play in doubles, is a bonus.

"We've had a great season in grand slams for singles. We've made the second week every single one, which has been really special.

"Now we'll sit back, reflect, and look forward to a big couple months to finish off the year."

World No.18 Wang was the highest-ranked rival Barty had played since the French Open semi-finals two months ago - and she was simply unable to rise to the occasion.

Formerly coached by Australian Davis Cup winner, the late Peter McNamara, Wang was like the Great Wall of China, her relentless defence and counter-punching driving Barty mad.

The second seed's numbers told the story, Barty committing 39 unforced errors in 18 games and unable to convert any of nine break-point chances.

"Q was very good, very solid. I felt like she was able to put the ball with great depth in difficult positions for me," Barty said.

"I still was able to create opportunities. Just very frustrating that on the big points today, Q played a lot better.

"It's frustrating now. Again, give me an hour and I'll be right. It's an opportunity, it's a new day tomorrow.

"Just because we've had a tough hour and a half on the court, it doesn't reflect on the year that I've had or the couple of weeks I've had here in New York.

"It's still going. Still have an opportunity to try to do well with Vika (Azarenka) tomorrow."

Champion last year with Coco Vandeweghe, Barty and Azarenka are through to the last 16 of the women's doubles.

The eighth seeds will play either American teenage prodigies Coco Gauff and Caty McNally or the Czech American pair of Kvete Peschke and Nicole Melichar for a place in the quarter-finals.

"Obviously playing with Coco last year, I had every intention to play with Coco in Australia (at the start of the year), kind of begin that again," Barty said of her switch in partners.

"But after her (ankle) injury, it was a bit of a last-minute thing where I just texted Vika and said: 'Look, I don't have a partner. Would you be keen to play in Australia?"

"We've just kind of gone from there."

with AAP