Anett Kontaveit upset Caroline Wozniacki in straight sets to reach the semi-finals of the Internazionali d'Italia on Friday.

Having knocked out Venus Williams in the previous round, Estonian Kontaveit continued her giant-killing run as she crushed the second seed 6-3 6-1 after one hour and 14 minutes on court.

Wozniacki - who had laboured to a three-set victory over Anastasija Sevastova on Thursday - turned in a below-par display, struggling particularly with her service game as she tumbled out of the tournament.

Kontaveit - who also reached the last four at the Porsche Tennis Grand Prix in Stuttgart last month - broke her opponent six times in all.

Neither player managed to hold in the opening four games of the contest and while Wozniacki eventually ended the run, she never led again after edging 3-2 ahead.

With her powerful backhand working to great effect, Kontaveit wrapped up the opening set with a forehand winner before breezing through the second, wrapping up the win with an ace.

She will next face Elina Svitolina, the defending champion having extended her winning streak in Rome to eight matches with a 6-4 6-4 triumph over Angelique Kerber.

The fourth seed triumphed for a sixth straight meeting against the former world number one, though she had to recover from 4-2 down in the first set.

"It was a good match. I had to really step up and play really aggressive in important moments," Svitolina told the WTA Tour.