MADRID, Spain - As the Mutua Madrid Open Virtual Pro innovation draws nearer to the business end, the vibe has become more serious, with Fiona Ferro turning up the focus to defeat Sorana Cirstea 6-3 and Kiki Bertens battling to a 7-5 victory over Caroline Wozniacki in the semifinals.

Unlike previous matches, there was little in the way of banter between the players other than an occasional "Good shot!" or Ferro spurring her avatar on with a whisper of "Allez-allez-allez". But with the competitors' PlayStation 4 skills well-honed over the week, they were able to show off an increasing range of shots that made for some of the best-played points of the tournament.

Indeed, World No.53 Ferro's computer simulation was more demonstrative than either of the players at home, repeatedly celebrating her best points with dramatic fistpumps and waves. It was often deserved: though Cirstea stuck to a gameplan of all-out aggression, particularly off the backhand wing and at net - "This cross backhand is killing me," muttered Ferro in the early stages - the Frenchwoman was able to counter it with superlative defence.

Frequently wheeling out the dropshot, Ferro's variety was also impressive. Moreover, the Lausanne champion weathered some bad luck to close out the match: having captured the first break for 5-3, Ferro was two points from victory at 30-30 when the stream froze. On resumption, having to restart on Cirstea's serve, the 23-year-old held firm to come through an epic game to take her fifth match point with a wrongfooting forehand winner.

"It was really fun to play with Sorana," Ferro said afterwards. "She's really aggressive and she's taking the ball really early, so it's like reality and a tough match for me."

Ferro will face defending champion Kiki Bertens in the final after the Dutchwoman turned in a near-reprise of her quarterfinal defeat of Belinda Bencic to end Caroline Wozniacki's run: both matches saw the World No.7 rock-solid on serve, never facing a break point, and sealing victory by breaking serve in the final game. Though Wozniacki was razor-sharp behind her own delivery through the first 10 games, reeling off a series of quickfire holds, the Dane could not find an answer to the 10 aces Bertens hammered down.

Key to Bertens' success was her willingness to take balls out of the air, even from mid-court, to rob Wozniacki of time. Having garnered no break points until the final game, the 28-year-old would snatch the win with two volleys from that position. "There was more chance for me there because she was only hitting winners," said Bertens of her tactics afterwards. "And it was working, so I had to keep doing it!"

The motion of several of the Bertens avatar's strokes bears an uncanny resemblance to the real-life player's style, and the St. Petersburg champion said that she was aiming to bring another of her own traits to the virtual game: "On the court I'm always trying to find a way to win, doesn't matter how - so today I did the same," she said.

Bertens and Ferro have been practice partners for each other leading up to the tournament, and the former foresees a tight match: "I've played a few times with Fiona and sometimes she was winning, sometimes I was winning - it's going to be really tough, may the best one win!" she said.

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