An emotional Alize Cornet said "it is never too late to try again" after reaching her maiden grand slam quarter-final with victory over Simona Halep at the Australian Open.

Cornet, who celebrated her 32nd birthday on Saturday, battled to a 6-4 3-6 6-4 victory in stifling conditions on Rod Laver Arena to set up a last-eight showdown with Danielle Collins, who beat Elise Mertens in three sets.

The Frenchwoman has now defeated two in-form former number ones in Halep and Garbine Muguruza, having also recovered from a set and 1-4 down to overcome Tamara Zidansek.

She is through to her first quarter-final in what is her 63rd grand slam appearance and is the first Frenchwoman to reach this stage at Melbourne Park since Marion Bartoli in 2009.

Cornet is playing in her 60th straight major, and should she compete in the main draws at Roland Garros, Wimbledon and Flushing Meadows, will set a new record for consecutive appearances in grand slams.

"It feels amazing," Cornet said in her on-court interview with Jelena Dokic. "It was a battle with Simona today. In this heat after 30 minutes we were both dying on the court.

"We kept going for two and a half hours with all our heart. Congrats to Simona because I know she struggled a lot and I admire this player so much. 

"She's such a fighter and an example to me. To beat her today to go to my first quarter-final is a dream come true. I don't know what to say. It's just magic. It's never too late to try again.

"This is why I keep playing tennis, for this moment where I can share all these emotions on the court with you."

Cornet had reached the last 16 at majors on five occasions prior to her victory over Halep in a run dating back 13 years when narrowly missing out on the Australian Open quarter-finals.

She was pegged back from a set and break up against Halep, losing 16 straight points at one point, and was clearly struggling with the heat as the match dragged into a decider.

But Cornet, who recently suggested this might be her final season playing professional tennis, showed incredible resolve to break Halep in the seventh game and hold her own serve to break her quarter-final hoodoo.

Halep congratulated Cornet, posting to her official Instagram account: "You have been stronger today! All the respect for you, Alize. Enjoy. I'll keep working to get better for another three-hour match when we meet again."

In her post-match media duties, Halep said: "I have only nice words about her, because I like her on court, how she's fighting.

"She deserves what is happening to her now. She works hard all the time, and I wish her good luck. I really want her to make this dream coming true."

There was to be another emotional moment for Cornet at the end of her victory speech as she praised 2009 Australian Open quarter-finalist Dokic for her work off the court since retiring eight years ago.

"I want to thank my box, but also I want to tell you something... how you moved on in your life, I think we can all congratulate you. You were an amazing player and now an amazing commentator," Cornet said as the pair embraced on court.

Dokic, who last week called out social media trolls for body-shaming her, responded: "You just made me cry. I can’t believe I'm crying. Thank you. Alize Cornet."