Safina struggles through to semifinals

LONDON, June 30 (UPI) -- World No. 1 Dinara Safina struggled Tuesday but was able to advance to the semifinals of the Wimbledon Championships in London.

The top four seeds -- Safina, No. 2 Serena Williams, No. 3 Venus Williams and No. 4 Elena Dementieva -- all made it through Wimbledon's quarterfinals with only Safina being pushed.

Safina hadn't dropped a set in the tournament but hadn't been completely sharp, either. That was the case in the quarterfinals where Safina battled through a 6-7 (5-7), 6-4, 6-1 victory over Sabina Lisicki.

Safina had 38 unforced errors and 15 double faults against 23 winners. It wasn't until she posted a break in the seventh game of the second set that things began to go her way. She finished by winning the last five games of the match.

Safina's semifinal opponent Thursday will be defending champion Venus Williams, who dispatched 11th-seeded Agnieszka Radwanska in 68 minutes Tuesday. Williams won the first five games of the match and the last six in completing the rout. Williams owns a 2-1 career advantage over Safina.

Serena Williams rolled 6-3, 6-3 over Victoria Azarenka and had just seven unforced errors. Dementieva, who defeated Francesca Schiavone 6-2, 6-2 on Tuesday, has dropped as many as three games in a set just twice in the tournament.

Serena Williams leads their head-to-head series 5-3.