Sharapova defeated by Dementieva

Dementieva had to battle for her straight-sets win

Elena Dementieva beat fellow Russian Maria Sharapova to reach the final of the JPMorgan Chase Open in Los Angeles.

Top seed Sharapova, who won last week's Acura Classic in San Diego, lost the first set 7-5 in just over an hour after battling back from 1-5 down.

Dementieva, the third seed, then benefited from a series of unforced errors to win the second set 6-2.

Dementieva will meet Jelena Jankovic after the Serb beat America's Serena Williams 6-4 6-3 in the other semi.

Sharapova reached the final without dropping a set and beat Dementieva in straight sets at both Indian Wells and Wimbledon earlier this year.

"I feel really great," Dementieva said. "I have lost to her twice this year and I was really looking forward to this match because she is such a tough player.

"This win really means a lot to me. When you play against Maria, she is a great fighter and never gives up. That makes it difficult to play against her."

Sharapova saved six match points on her serve in the final game, but she when she handed Dementieva a seventh by hitting a forehand into the net it was one too many - Sharapova hit another forehand long.

Serena's one of the hardest hitters out there but I returned really well, and I think that made the difference Jelena Jankovic

Sharapova blamed fatigue for her error-strewn display.

"I haven't played this much in a while," she said. "A year ago, I would probably haven't been able to play solid tennis for nine matches as I've been doing."

Williams was given a wildcard for the LA event after dropping out of the top 100 during a six-month injury lay-off this year.

She enjoyed a good run to the semi-finals, but 16th seed Jankovic refused to be intimidated by her power.

The 21-year-old returned superbly, was rock-solid at the net and controlled most of the rallies from the baseline.

She broke her opponent's serve in the 10th game of the opening set before Williams was warned for racket abuse.

And although severely tested by Williams on her own serve, Jankovic broke her again in the fourth game of the second set to pave the way to victory.

"Serena's one of the hardest hitters out there but I returned really well, and I think that made the difference," she said.