The top four seeds will contest this year's Wimbledon semi-finals after winning their last-eight ties on Tuesday.

Maria Sharapova was the first to book her place in the semis with a 6-1 6-4 defeat of Elena Dementieva.

Sharapova started the all-Russian clash like a train and raced through the first set in just 27 minutes.

The 2004 champion surged 4-0 ahead in the second set but then lost three games in a row - after a streaker disrupted play on Centre Court - as Dementieva threatened to turn the match into a contest for the first time.

She made Sharapova serve for the match at 5-4, but the 19-year-old proved up to the task and set up a semi-final meeting with top seed Amelie Mauresmo who beat Anastasia Myskina 6-1 3-6 6-3.

Mauresmo dominated the first set, winning six games in a row to clinch it but Myskina hit back well in the second.

The Frenchwoman, notorious for letting decent positions slip, steeled herself in the decider and gained the only break of serve in the sixth game to progress to her fourth semi-final in SW19.

"Winning through is the most important thing and I have an opportunity on Thursday to play better,'' said the world number one.

"It is my fourth semi-final here and I have another chance to go to the final.

"I am feeling good physically and I enjoy playing here.''

On the other side of the draw, Justine Henin-Hardenne saw off French qualifier Severine Bremond 6-4 6-4.

Henin-Hardenne has not been beaten by a player ranked outside the top 100 in over four years - Bremond lies 129th - and that statistic was never under threat.

But the 24-year-old will be keen to improve her serve which wasn't at its best.

She was broken in both sets by Bremond and looked vulnerable at times, although she proved too classy for her opponent in the end.

"When you are in the semis or even in the quarters, everyone is playing good tennis - but you need to deal with the situation and that is what I am trying to do right now,'' said the Belgian, runner-up at the All England Club in 2001.

"Let us go step by step - I hope I have another opportunity to play another final here in Wimbledon, and that is my next goal.

"But it is going to be a tough mission for me on Thursday. I will try to give my best, as always.''

It will be an all-Belgian semi-final as Kim Clijsters followed Henin-Hardenne into the last four later in the day.

The second seed was made to fight by China's Na Li before winning 6-4 7-5.

Li was China's first-ever Grand Slam singles quarter-finalist and she did herself proud.

She launched a fightback in the second set and led it 5-2.

At 5-4 she missed set point and never recovered from that setback. She duly lost the remaining games to slip to defeat.

Looking ahead to Thursday, Clijsters said: "Justine is playing great tennis and I am looking forward to it.

"It should be a great match.''