STUTTGART, Germany - Jelena Jankovic defeated Alisa Kleybanova, 64 63, to wrap up Quarterfinal Friday at the Porsche Tennis Grand Prix. Three former World No.1s are among the final four line-up.

Watch highlights, interviews and more video from Stuttgart right here on wtatennis.com!

The Plot
Kleybanova had a lot in her favor going into this match. Not only did she upset Petra Kvitova in the last round, her first Top 10 win since coming back from her battle with Hodgkin's lymphoma, but she had also had fairly good success against Jankovic in the past, winning three of their seven previous encounters - including twice while Jankovic was ranked in the Top 4, once at No.4 and once at No.2.

The Turning Point
The No.5-seeded Jankovic came out of the blocks too fast in both sets of their latest encounter on Friday. She broke serve in the very first game of the match, a break of serve she would ride all the way through to the end of the first set, and she broke again in the first game of the second set. Kleybanova would get that break back, but from 3-all it was all Jankovic, as she cruised to victory from there.

By The Numbers
Though Kleybanova was clearly the aggressor during the match, Jankovic's consistency was far more powerful in the end. She had an almost even differential of winners to unforced errors during the match of -2 (15 winners to 17 unforced errors) while Kleybanova was -8 (23 winners to 31 unforced errors).

What's Next
Awaiting Jankovic in the semifinals is No.9 seed Ana Ivanovic, who outdid Svetlana Kuznetsova earlier in the day, 63 26 64 (read more about that match here). Ivanovic leads their head-to-head series, 8-3, and has won their last two meetings in straight sets, but Jankovic did win their last clay court meeting.

Also advancing to the semifinals were No.6 seed Maria Sharapova, who beat No.1 seed Agnieszka Radwanska, 64 63 (read more here) and No.8 seed Sara Errani, who won by retirement over Carla Suárez Navarro, 63 67(6) 30, when the Spaniard stopped due to a wrist injury (read more here).

Quotes
"It's better that Ana and I are playing the semifinals because one of us will be in the final, and it's great for our country," Jankovic said. "It's going to be great for either one of us to be in the final, to be competing for the Porsche. It will be a tough match, of course. We've had really tough matches in the past and she's playing quite well at the moment, though I hope to be playing well as well.

"Hopefully it will be a good match tomorrow and the better player will win."