Simona Halep believes the run to the Australian Open last 16 by Coco Gauff is a "great thing" for tennis and expects the 15-year-old to win a grand slam "soon".

Gauff stunned defending champion Naomi Osaka in the third round to match her best career performance at a major, which she previously achieved at Wimbledon.

The American was knocked out by eventual tournament winner Halep in the fourth round at the All England Club.

Both players are in contention for glory in Melbourne after the fourth seed joined the teenager in round four with a 6-1 6-4 win over Yulia Putintseva on Saturday.

Halep was asked about the contrast in women's tennis between Gauff thriving at 15 and Caroline Wozniacki retiring at 29 at a time 38-year-old Serena Williams is soon to be re-joined by another veteran in Kim Clijsters.

"Well, it's kind of a big mix here with the 15-year-old that is winning matches in a grand slam and makes it look easy," said the 28-year-old.

"And a 29-year-old retiring, so I'm very close but, yes, I hope not yet! But also we have a 38-year-old still playing, Serena. Everyone has their own feelings about this sport. 

"What Coco Gauff is doing in this moment is a great thing. I'm sure that she gets a lot of confidence, and soon she will be able to win one of these big tournaments.

"And about Kim it's really nice to hear that she's coming back. I played once against her and I lost. 

"Maybe I will have another chance to play against her, because actually, she was a model for me growing up, so I look forward to see her back on tour."

Gauff will meet compatriot Sofia Kenin in the last 16 while two-time grand slam winner Halep takes on Elise Mertens.

Osaka has discussed the pressures of returning to the top events as a major champion but Halep feels her previous successes at the French Open and Wimbledon give her an advantage.

Halep said: "It was different because I played few finals before and actually I felt that it's really tough to get one. 

"After I did it, I felt like, okay, it's really tough but it's possible. Everything is possible.

"So maybe I relaxed a little bit more and I don't see that these tournaments are so out of reach anymore. So I feel more confident."

And Halep insisted seeing Williams, Osaka, Karolina Pliskova, Elina Svitolina and Belinda Bencic crash out in the early stages does not make her worried about being the next victim of an upset.

"I hope not," she said. "I just take the responsibility on my game, and I have expectations for myself, but I know that everything can happen. So I'm ready to fight for every match I play. 

"I know at this level everything can happen, so that's why sometimes I'm a little bit stressed, sometimes I'm relaxed.

"It's just a tournament, and I'm sure that for you guys it's a little bit of shock when the top-10 players are losing, but it's life and we cannot be 100 per cent every day. So we go ahead, and if I'm still in the tournament, it's a good thing."