The 22-year-old came from behind to oust the former world no.1 Maria Sharapova 4-6 6-1 6-4.

She becomes the first Australian women first Jelena Dokić in 2009 to reach the quarter-finals of an Australian Open. It is also the first time she has reached the final eight at a Grand Slam.

It was a close match, with the crowd and those around their TV at home sitting on the edge of their seats as Sharapova brought the game level after being down 15-40. 

Hands were on mouths as Barty got an advantage and it was a beautifully placed ace that sealed the win.

"It was a little close, wasn't it," Barty said on the court post-match.

"I gave myself the opportunity in the third set in a lot of games and just couldn't take it so just had to take a deep breath and trust the work I've done with my team."

Sharapova, a former winner in Melbourne, has been playing some great tennis at the tournament, even defeating reigning Champion Caroline Wozniacki in the third round.

Although there wasn't much separating the two players, it was experience that saw the world no.30 take the opening set. 

However, Barty put her foot down in the second, breaking Sharapova twice and winning nine straight games. 

The five-time Grand Slam winner wasn't going to bow out this way winning the next three games to bring it to 3-4 in the third set.

Taken by Ben Southall (@bsouthallau)

During her on-court interview, Barty praised her former WBBL side, Brisbane Heat, on making the Grand Final.

"I think I was pretty wrapped yesterday, the Heat girls made the final but that was a hell of an afternoon yesterday," she said.

Barty will now face two-time Wimbledon champion Petra Kvitova, in what is a rematch of last week's Sydney International final.