Navarro, Muguruza into Sofia semi-finals

Sofia (AFP) - Carla Suarez Navarro, Garbine Muguruza and Flavia Pennetta completed the semi-final line-up at the WTA Tournament of Champions on Friday joining Andrea Petkovic in the last-four.

Fifth-seeded Navarro enjoyed a 7-6 (7/2), 6-1 win over eighth-seeded Tsvetana Pironkova to finish top in Group Sredets, with Petkovic in second place.

"If I lost a set today I would be out, so if I missed on one of the set points I would have been out, so I was pretty nervous on the court today," Suárez Navarro said.

"She was playing very well in the first set, too. But I was just trying to do my best and I'm happy I could make it through to the semi-finals."

Fellow Spaniard Garbine Muguruza, the seventh seed, improved to 3-0 in Group Serdika with a 6-3, 7-5 win over Alize Cornet.

"The second set was really difficult because that was the moment I realized I could win," Muguruza said.

Muguruza not only secured first place with the win, she also brought Pennetta along with her into second place.

Third-seeded Pennetta didn't disappoint, beating alternate Karolina Pliskova, 6-1, 6-3.

In Saturday's semi-finals, Muguruza plays Petkovic while Pennetta tackles Suarez Navarro.