ROME, Italy - No.4 seed Elina Svitolina continued her march towards a title defense at the Internazionali BNL d'Italia on Friday with an emphatic 6-4, 6-4 victory over former World No.1 Angelique Kerber.

Despite starting slowly for the second straight match after falling behind 4-2 in the opening set, Svitolina turned the match around to score her sixth straight win against the two-time Grand Slam champion and eighth straight victory in the Italian capital.

The Ukrainian won the last four games of the first set to move ahead, and was the first to settle on serve after the second set began with five straight service breaks to punch her ticket back to the final four in Rome.

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

"That's what was the key for today. I played really good on the important points. That's what made a difference."

Having lost just one set against the World No.12 in their last five meetings, Svitolina looked in danger of dropping a second early in the match, as she was tested in each of her first two service games.

"I don't think about those kind of things, because it can play a little bit on your mind. I just take one point at a time, one game at a time, and that's what matters the most to me," Svitolina said of her streak against the German No.2.

"She played good tennis matches earlier rounds. I was expecting there would be a tough match. She had a good start, as well. For every player these days, everyone can play really good tennis and...can give you some problems. That's why for every match I try to prepare and try to be ready 100%."

After taking each game to deuce, Kerber finally broke through in the sixth game of the opener on her third opportunity, and looked to build on an early stretch of form which saw her win nine straight points on serve.

However, the German was unable to convert on a game point which would've given her a 5-2 lead, and later lost a 40-15 advantage on serve en route to dropping serve for the second time - and the set.

Svitolina struck 29 winners to 25 unforced errors over the course of one hour, 26 minutes, edging Kerber - who struck 26 winners and 29 unforced - in both stat lines.

The Ukrainian won five of eight break points she created in the match, but it was the deterioration of Kerber's serve in the second set which helped Svitolina clinch victory.

Though Svitolina was twice ahead by a break, the German hit back each time but was unable to capitalize on the momentum in a lengthy fifth game - where she served five double faults, including one on break point. 

That break proved to be the decisive one for the defending champion in the match, as she saved two break points in the next game and held for the rest of the match to set up a semifinal meeting with either No.2 seed Caroline Wozniacki or Anett Kontaveit.

"This is one more step in the right direction. I'm playing good tennis. I'm happy on court. I'm moving good. I'm happy the way I'm handling, so far, the pressure," Svitolina added. "That's important for me, all those small things which makes a big difference. That's what I've been striving for, and hopefully, I can do the same in the next match.

"I know both players that I'm gonna face next round. I know the game they play. They play differently. Of course, I'm going to have a plan for my next match, but for me, it's very important to be ready physically, to be ready mentally to fight and to be ready to present my best game.

"That's very important, and then it doesn't matter who's on the other side of the net."