Tennis legend Ash Barty has downplayed the impact of a controversial medical time-out used by her opposition Karolina Muchova which caused Barty to lose at the Australian Open.

Barty's surprising loss has left tennis fans and experts shocked, with the rules coming under fire.

“I was a bit lost on the court and my head was spinning so I took a break and it helped me,” Muchova said after the match.

“I started feeling a bit lost by the end of the first set. Ash started very good. She played like no mistakes. It was very tough.”

It seemed Barty was unable to recover after the 10-minute medical break and lost nine out of 11 games from the end of the second set to the end of the match.

She refused to bite when pressed on the incident in a press conference.

“I don’t write the rules. I abide by them. All of us players, we abide by the rules that are written,” Barty said.

“If she wasn’t within the rules, the physios and the doctors would have said so. That’s the laws of our game, that we have those medical time-outs for cases that are needed. Obviously she needed that today.

“I’ve played a lot of matches where there have been medical time-outs. I’ve taken medical time-outs myself before, so that shouldn’t be a massive turning point in the match,” she said.

“I was disappointed that I let that become a turning point. I’m experienced enough now to be able to deal with that.”

Twitter was ablaze with theories, including one from former World no. 3 and doubles great Pam Shriver.

“(It) seemed legit, but it still does not sit well when it pivots a match on a dime,” Shriver said.

“Muchova has won 7 of 8 games since leaving the court. Thoughts anyone?”

“I am not blaming her, absolutely blaming the ridiculous rule that allows this to happen,” former world No.4 turned successful coach Brad Gilbert said.

Former NBA player Jason Collins weighed in on the debate as well.

“(Medical time-outs have) been a part of the sport. As a competitor you have to mentally prepare for any kind of gamesmanship from your opponent,” he wrote.

“For example— We all know that if you’re up early against Novak (Djokovic), get ready for a MTO or racket smashes or long conversations with him & the chair (umpire).”

Barty admitted that it felt "impossible" to turn the tide after the 10-minute medical break.

“I felt like I had small windows of opportunity probably midway through the second set and wasn’t able to kind of regroup enough to be clear in the third set how I wanted to play,” Barty said.

“I think I just lost my way a little bit, which is disappointing without a doubt.”