LONDON, England - Maria Sharapova and Maria Kirilenko moved into the semifinals of the Olympic Tennis Event on Thursday, fending off some very big-hitters in straight sets to guarantee Russia one - and maybe two - medals.

The No.14-seeded Kirilenko was the first to advance, pulling off a surprise win over No.6-seeded Petra Kvitova, 76(3) 63. There were no breaks of serve in the first set as both held on tightly to their delivery, but it was Kirilenko who lifted her game in the tie-break; the Russian then got the only break of the match to lead 5-3 in the second set, then smoothly served out the monster win.

"It's a dream," Kirilenko said. "I had some tactics to play today and I did everything I planned, and it went well. I'm so happy with this result."

"Maria played better today - she was faster and served well," Kvitova said. "It was windy and I think I could have played better, but all the credit to her."

On match point, Kirilenko shanked a few shots that landed extremely deep, and Kvitova missed into the net. "It was quite windy out there," Kirilenko said. "Match point was a tricky point. There were some lucky shots from both sides, and when you're getting close to winning of course you have some nerves."

Next up for Kirilenko will be the No.3-seeded Sharapova, who ended the run of fellow four-time Grand Slam champion and former No.1 Kim Clijsters, 62 75. The early goings looked completely one-sided as Sharapova cruised through the first set and broke early in the second set; Clijsters broke back, but Sharapova got another break at 5-all then - like Kirilenko - smoothly served it out.

"I knew I had to step it up today and stay extra focused," Sharapova said. "Kim is such a tough competitor. Obviously she has won so many Grand Slams. She has endless experience. We've always had difficult matches, and I was really happy I was able to step it up today, compared to my previous matches here.

"An opponent like Kim can obviously turn the match around at any time."

Clijsters, who was playing her second-to-last tournament, was gracious in defeat. "Of all the matches I've played against her in my career, this is the best she has ever served. On grass it's going to be tough to beat her.

"It was great. It's a nice experience every time you go out on Centre Court. I'm so happy to say my last match at Wimbledon was on Centre Court."

An all-Russian semifinal at the Olympics means one will win gold or silver, and the other could win the bronze. Sharapova was asked about the Russian spirit.

"When I was growing up, tennis wasn't very popular yet. A few men's players were, especially Kafelnikov. But apart from that, in the women's field there wasn't too much competition. So I hoped one day that could be different.

"You've seen over the years how much it's developed in Russia, how many more opportunities there are for younger kids starting up, opportunities maybe I or the othes in my age group didn't really have, as far as facilities, coaching, all of that.

"I'm really happy one of us will have a chance to go for gold."

Sharapova leads Kirilenko in their head-to-head series, 3-2. Sharapova won their only previous 2012 meeting at Indian Wells, though she had to rally from 63 20 down to do it. This will be their first career meeting on grass.