Two-times Wimbledon champion Petra Kvitova told a Czech court on Tuesday how she grabbed the blade of an attacker's knife and forced it away from her neck, leaving blood everywhere, during an attack at her home in December 2016.

Kvitova suffered severe wounds to her playing left hand as she struggled with the knife-wielding intruder. She returned to professional tennis in May 2017, crowning her comeback 18 months later with her first final appearance at 2019 Australian Open.

Giving testimony in the trial of a 33-year-old man charged with her assault, Kvitova said she had felt no pain when the 10-inch blade cut into her hand.

To avoid direct confrontation with the suspect during the trial, Kvitova sat in a separate room at the Brno regional courthouse, giving a detailed account via microphone and camera of how the man entered her apartment and then attacked her.

The man had rung her doorbell at 8:30 a.m. posing as a workman come to inspect the hot water system in the flat, a Czech news website quoted her as saying.

"He asked me to turn on the hot water tap and at that moment I had a knife against my neck. I grabbed it with both hands. I held the blade with my left hand. I snatched it away, I fell on the floor and there was blood everywhere," she said.

Kvitova described how she tried to reach her mobile phone on the carpet but he pushed it away. She told him she needed to go to hospital and asked whether he wanted money.

"He asked how much I had. I said ten thousand crowns (€386) and he said 'OK'. I gave him the money, he left and I called the ambulance and then the police," she added.

Though she had felt no pain when the attacker cut her hand, Kvitova said: "When I saw the blood, I started blubbing."

"All the fingers on my left hand had been cut, and the nerves in my thumb and index finger severed. Even today, the mobility is not 100 percent. There is no sensitivity in the tips (of my thumb and index finger)."

Kvitova said she had recognised her attacker in photos provided by the police.

"I knew it was him the moment I saw him (in the pictures). I remembered his eyes mainly."

The suspect faces up to 12 years in jail if convicted. He has already been sentenced to 2.5 years in a separate case. His trial in the Kvitova case will continue with the testimony of experts.