An appeals court in the Czech Republic has upheld a lower court conviction of a man for knifing two-time Wimbledon champion Petra Kvitova in her home and increased his sentence from eight to 11 years in prison.

The regional court in the city of Brno ruled in March that Radim Zondra caused Kvitova serious bodily harm in December 2016 when he attacked her in her apartment in Prostejov.

The state prosecutor requested 12 years in prison for Zondra, who pleaded not guilty and appealed.

The prosecution also appealed and the High Court in the city of Olomouc handed Zondra an 11-year prison term on Wednesday.

The verdict is final.

Kvitova had surgery on injuries to her playing left hand. It took the tennis star more than five months to recover.

She is at the Brisbane International this week, warming up for the Australian Open, where she reached the final last year.