Caroline Wozniacki fought back from the brink of defeat to reach the third round of the Australian Open along with 15-year-old Marta Kostyuk, but Julia Goerges' long winning run came to an end on Wednesday.

Wozniacki was on the ropes at 5-1 down to the 119-ranked Jana Fett in the final set, but the second seed saved two match points and won six games in a row to pull off a remarkable 3-6 6-2 7-5 victory on Rod Laver Arena

Goerges had won 15 matches in a row before facing Alize Cornet, but the world number 42 from France brought the 12th seed back down to earth with an unexpected 6-4 6-3 success.

Last year's junior champion Kostyuk became the youngest player to win a main draw match in the first major of the year since 1996 when she beat Peng Shuai on Monday and the Ukrainian followed that up by toppling local wildcard Olivia Rogowska 6-3 7-5.

Goerges was not the only seed to bow out, Anastasia Pavlyuchenkova (15) going down 6-2 6-3 to Kateryna Bondarenko, Magda Linette toppling Daria Kasatkina (22) and home hope Daria Gavrilova (23) squandering a 5-0 lead in the first set before Elise Mertens sealed a 7-5 6-3 win close to 2am.

FAMILY FIGHTING SPIRIT SERVES WOZNIACKI WELL

Wozniacki is a major contender to finally win an elusive first grand slam this month at Melbourne Park after claiming the biggest title of her career at the WTA Finals and making a promising start this season.

The former world number one looked set to suffer a stunning upset at the hands of 21-year-old Croatian Fett, making her grand slam main-draw debut, but drew on a fighting spirit ingrained from her childhood to set up a meeting with Kiki Bertens.

"I think growing up in a sporty family where everyone is competitive and you hate to lose [helped]," said the tenacious Dane. "If you lose a game to anyone in my family, you're going to hear about it for at least a week. That definitely helped me.

"Growing up, I never wanted to lose, and the worst was to lose to my brother. Giving him the opportunity to be ahead, being able to talk s*** to me was not pleasurable. So I think from that point, you just learn and fight. You don't give up, even if it's a board game, tennis, soccer, whatever it is."

GOERGES FINALLY COMES UNSTUCK

An in-form Goerges was talked up as one of the many contenders to win the title after beating Wozniacki in the Auckland Open final.

That was her third successive tournament triumph, but the world number 12 finally met her match in the form of Cornet, who broke three times to beat Goerges for the first time after losing their previous five encounters.

Goerges said: "I must be proud of what I have achieved in the last weeks and months. It's sad to go out of a grand slam early but it doesn't bring me down from working hard and keeping improving. It's going to be a great season, I'm sure."

SVITOLINA NEXT UP FOR TEEN SENSATION KOSTYUK

Kostyuk has certainly made a name for herself in the opening week, shocking Peng before getting past Rogowska.

The teenager, playing with a strapped-up left ankle on Margaret Court Arena, will now face fourth seed Elina Svitolina in an all-Ukrainian third-round match.

Kostyuk said of facing her compatriot: "I will just enjoy it. I think I'm going to play on a big court again, I will just try to show my best tennis, because I'm pretty sure, like all my opponents, she will struggle a little bit, and I will try to make the most of that.

"That's what I'm going to do. I know a little bit how Elina is playing, but I will not go into the details."

VENUS VICTORY A FALSE DAWN FOR BENCIC, OSTAPENKO THROUGH

Belinda Bencic claimed the scalp of fifth seed Venus Williams in the first round, but was on the wrong end of an upset two days later.

Luksika Kumkhum, the world number 125, made light work of sending the Swiss packing, taking only an hour and 18 minutes to win 6-1 6-3 on Hisense Arena.

French Open champion Jelena Ostapenko beat Duan Ying-Ying 6-3 3-6 6-4, while Svitolina came from a set down to defeat Katerina Siniakova 4-6 6-2 6-1.