Two years ago, Petra Kvitova opened her front door. Then, a man pulled out a knife.

It was a Tuesday in December, freezing cold in Prostejov, Czech Republic, when Petra Kvitova’s doorbell rang.

Only hours before, the two-time Wimbledon champion had pulled out of the Hopman Cup held in Perth, due to a foot stress fracture which refused to heal.

The 26-year-old was devastated. Five years before she had been ranked world number two in the world after beating Maria Sharapova in straight sets at the final of Wimbledon.

Now, she was housebound.

On that Tuesday, she answered the door. It was a tradesman, there to check her utility meter.

At least that’s what she thought.

The man, believed to be in his 30s, would execute an attack on Petra that would threaten her professional tennis career, both physically and psychologically.

They were both in the bathroom when the man first attacked her. Petra fought back, only to be confronted with a knife, which was held to her throat.

During the struggle, the bronze medallist sustained multiple stab wounds to her left hand – the same hand she uses to hold her racket.

In the moments that followed, the young woman fought off her attacker. After he fled, Petra called emergency services, and was transported to a hospital almost 65 kilometres away.

It took almost four hours for doctors to repair the tendon damage in all five of her fingers, as well as damage to two nerves.

The nerve injuries, according to Dr Michael W. Kesller, a chief hand and elbow surgeon, were likely going to cause the most disruption to Petra’s tennis career. Nerve damage results in numbness, meaning a player cannot receive the same “feedback from the fingertips” that they had likely come to rely upon.

But Petra – who believed her best tennis was still ahead of her – never saw her injuries as potentially career ending.

Spokesperson for the Czech Fed Cup team, Karel Tejkal, said on her behalf, “The end of her career did not even cross her mind… she kept saying ‘Let them put me together fast, no matter if it takes month or years’.”

On Tuesday night, almost exactly two years after the brutal attack, 28-year-old Petra won the quarter-final of the Australian Open – a tournament stolen from her in 2016.

Now ranked number eight, Petra beat 22-year-old Australian Ash Barty in two sets.

During her post match interview with Jim Courier, she said, “I didn’t imagine I’d be back here on this stage. It’s great.”

A pause from Petra, where tears fell down her cheeks, was filled with cheers of encouragement from the crowd.

“I’m seeing life a little bit differently compared with before. I know it’s just the sport, it’s just the tennis,” the semi-finalist later said.

Petra has embarked on what she’s calling her ‘second career’ – a life following the attack.

She’s currently in the midst of a 10-match streak, seemingly unable to lose.

Two years ago, Petra watched the Australian Open, with a broken foot and a shredded hand.

Could she, in 2019, win the championship she so desperately wished she could play?

It’s looking increasingly likely.