Radim Zondra, 33, went to her flat in 2016 saying he needed to inspect the boiler. He then grabbed Kvitova from behind and held a knife to her throat.
She suffered severe wounds to her left hand in the fight to free herself but returned to tennis five months later.
Appearing at a regional court in Brno, Zondra denied all charges against him.
Zondra, who is currently serving a prison sentence for another crime, was convicted of serious battery and illegal entry into Kvitova's apartment.
The 29-year-old player, who is currently the world number two, told the courtlast month there was "blood all over the place" after the December 2016 attack.
She added that she had offered Zondra money to leave, eventually giving him 10,000 Czech crowns (£341; $440). The court has ordered him to pay this back.
In her judgment, Judge Dagmar Bordovska said Kvitova's testimony was credible, while witnesses who testified on behalf of Zondra were unreliable, CTK news agency reports.
Although Zondra denied ever being in the tennis star's home, prosecutors argued that DNA evidence and the positive identification from Kvitova meant he was guilty beyond all doubt.
The two-time Wimbledon champion suffered damage to ligaments and tendons in her playing hand, and underwent a four-hour surgery.
Doctors warned her at the time that her tennis career could be over and that she may even lose her fingers.
However she returned to tennis in May 2017, following months of rehabilitation, and continued her successful career.
Earlier this year she reached the Australian Open final, and is now in the US competing in the Miami Open. She will face Ashleigh Barty in the quarter-finals later on Tuesday.