STUTTGART, Germany -- No.6 seed Kiki Bertens of the Netherlands blasted past two-time champion and No.5 seed Angelique Kerber of Germany, 6-3, 6-4, to ease into the semifinals of the Porsche Tennis Grand Prix on Friday.

"I think today was a really solid match, much better I think than yesterday," Bertens told the press, after her win. "I’m really happy with my performance. A little less aces than yesterday, but I think Angie is a great returner. I was still really happy with my serve. I didn’t face a break point, I think. So, it was just a really good performance."

Bertens, the World No.7, had split her previous four meetings with World No.5 Kerber, but it was the Dutchwoman who edged ahead in their head-to-head after taking the quarterfinal clash after 75 minutes of play.

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The Dutchwoman did not face a single break point during the match, as her stellar serving, which propelled her to 20 aces in her second-round win, stayed with her during her clash with Kerber. Bertens finished the quarterfinal with 29 winners to 21 unforced errors, while Kerber struggled in that comparison, hitting just 11 winners compared to 25 unforced errors.

"You always have to hang in there against Angie because she is just keeping on fighting for every point," Bertens added. "So, you never know what is going to happen. So, I really had to finish in a good way today."

Bertens moves through to the final four where she will take on No.3 seed Petra Kvitova of the Czech Republic. Kvitova reached the semifinals in Stuttgart for the third time in her career after she defeated No.7 seed Anastasija Sevastova in three sets earlier on Friday. Bertens and Kvitova have split their four prior meetings.

"It's going to be a tough match," Bertens admitted. "I think Petra is having a really good year so far, playing some great tennis. So, it’s going to be a really tough battle but I’m looking forward to it and hopefully I can play the same game as I played today."

As the match commenced, the huge hitting of Bertens came up against the pristine groundstrokes of Kerber and the players were deadlocked in this battle up to 3-3, with neither combatant facing a break point up to that juncture.

But after a stunning hold at love for 4-3 by the Dutchwoman, where her service appeared impenetrable, it was Kerber who faltered first, firing a miscue long in the following game to give Bertens a break point. There, the German double faulted, and Bertens suddenly had a commanding break advantage.

Kerber used her stellar court craft to pull herself to 30-30 as Bertens served for the opening frame, but a subsequent crushing overhead by the Dutchwoman gave her a set point. Kerber netted the service return to cede the one-set lead to the blistering game of Bertens.

Kerber kept grinding through the match, saving a break point in a lengthy game with a devilish down-the-line groundstroke to eke out a service hold at 2-1. But the two-time titlist was less fortunate in her next service game, as the power game of Bertens prevailed, breaking for a 3-2 lead with an awesome crosscourt return winner.

Bertens again had a look in on Kerber’s service game at 4-2, as the German needed to stave off a break point to stay just one break behind. Bertens, though, was resistant to any attacks by the former World No.1, as she cruised to another hold for 5-3.

Kerber grinded out another difficult hold to reach 5-4, and after a winner on the first point of the next service game, the German and her home-country crowd were anxious for this to be her chance to get a break. Bertens, however, coolly reeled off three points in a row to reach double match point, and ended the encounter on her second opportunity with an ace.