Serbs Jankovic and Ivanovic ease into last four

By Mark Lamport-Stokes

INDIAN WELLS, California (Reuters) - Third seed Jelena Jankovic reached the last four at the Pacific Life Open when American Lindsay Davenport retired from their quarter-final because of a back injury on Thursday.

The 31-year-old Davenport, twice former champion at Indian Wells, summoned her trainer when trailing Serb Jankovic 4-1 before deciding to withdraw after losing the first set 6-2.

"My back was injured before I came here but I got it better, got it better and then this morning woke up and just couldn't move," Davenport told reporters.

"It was pretty obvious to me after two games that I was pretty sore out there and it was quite hard to rotate.

"I was hopeful with all the medication I took and the treatments, but it just didn't happen," added the former world number one, champion at Indian Wells in 1997 and 2000.

Jankovic, who will face compatriot Ana Ivanovic in the semi-finals, was unaware of Davenport's injury before the start of the match.

"I just came out on the court with the goal I wanted to play her really aggressive and take the initiative from the first strike, and that's what I did today," the 23-year-old said.

"But I had no idea that she had some problems. I wish her to recover as fast as possible and to come back."