Zhang Shuai's courageous Australian Open win.

It’s not easy fronting up to your 15th grand slam knowing you’ve never even won a single match.

It’s probably even more difficult when you’re slated to play the world’s number two.

This was Zhang Shuai on Tuesday night.

The 25-year-old Chinese player, ranked 133 in the world, had even begun planning her life after tennis when she stepped onto Margaret Court Arena.

But in the end, Zhang dominated the court, beating world number two Simona Halep in straight sets, 6-4, 6-3.

It was all over in just under two hours.

What a win.

With tears streaming down her face, Zhang celebrated her upset (the second of the day after Rafael Nadal lost to Fernando Verdasco in a four-hour 42-minute battle) at the centre of the court amid rapturous applause from the crowd.

Australians really do love an underdog.

“So exciting today, played so well… for beating the top two player, I’m so happy, it’s so exciting,” she said afterwards.

“I want to thank my coach, my parents, thank you everybody that has come supporting me.”

In her post-match interview, she said she had planned on pursing a completely different life.

“I [was] feeling very sad every day. I almost retire,” she said.

So she decided to try one last time, at the Australian Open.

“I didn’t know how can keep going. But when even say, Okay, retire, no problem, nobody said, No.

“But I’m feeling no, I want come back. I want try one more time, only one more time, yeah. If no good, I say, Okay, I will try last tournament Australia Open.

“If Australia Open not good, maybe finish tennis. But I never think I can win in the here, win the first round,” she said.

But she did.

Zhang will face France’s Alizé Cornet, ranked 33rd, in the second round.