By Martyn Herman

LONDON (Reuters) - Maria Sharapova swaggered into the Wimbledon semi-finals with a formidable display every bit as spectacular as the thunder claps that rattled the All England Club on Tuesday.

The Russian fifth seed, the stand-out name in an unfamiliar looking last eight, roared to a 6-1 6-1 win over shell-shocked Dominika Cibulkova under Center Court's roof and now only wildcard Sabine Lisicki stands between Sharapova and her first final here since she won the tournament in 2004.

Lisicki continued her heart-warming run when she outlasted French livewire Marion Bartoli 6-4 6-7 6-1 to become the first German woman to reach the semis since Steffi Graf in 1999.

Both matches were played out in the slightly surreal atmosphere of a covered show court after Monday's sticky heat gave way to rumbling storms.

Play was eventually possible on the roof-less Court One where Czech Petra Kvitova beat Bulgaria's Tsvetana Pironkova 6-3 6-7 6-2 in just over two hours to set up a semi-final against fourth seed Victoria Azarenka.

Belarussian Azarenka reached her first grand slam semi-final when she thrashed 20-year-old Austrian Tamira Paszek 6-3 6-1 in match that started on Court One but was switched to Center Court after rain returned.

Azarenka, whose on-court decibel level has often eclipsed her tennis, said a talk with her mother earlier this year had helped her become a grand slam contender rather than a student.

"After the tournament in Doha I didn't really want to play tennis," she told reporters. "I just wanted to go home and rest. My mom asked me, Oh, what are you going to do? I said, I'm going to study. She laughed out loud."

The broad-shouldered 24-year-old lived up to that billing with an unrelenting display of high-voltage tennis to demolish a player she towered above both in stature and class.

"I haven't been at this stage in Wimbledon in a few years, so this feels great," former world number one Sharapova, who had not lasted beyond the quarter-finals at the grasscourt slam since 2006, told reporters after her winning in an hour.

"I would have loved for it not to have taken that long, but I'm not complaining. It's the road that you sometimes have to take. It's not always straight. There are a lot of zigzags."

There were few zigzags against the overwhelmed Cibulkova, just straight line speed as Sharapova thumped 23 clean winners and countless more unreturnable drives.

Even when 24th-ranked Cibulkova, who knocked out Wozniacki on Monday, earned a break point in the final game Sharapova simply cuffed a fizzing ace down the middle, a pinpoint shot that would have been appreciated by U.S. Open golf champion Rory McIlroy who watched from the Royal Box.


Impressive as it was, Sharapova's match was never really a contest, unlike the humdinger that preceded it.

With torrential rain drumming loudly on the Center Court roof Lisicki and 2007 runner-up Bartoli went toe-to-toe in some

before Bartoli's reserves of energy finally ran out.

"My legs were cramping, my mind was working but I ran out of gas and there's nothing I could do," the 26-year-old told, whose antics between points included frantic practice swings, sprinting on the spot and various skips, hops and slaps.

Lisicki missed five months in 2010 with an ankle injury, slumping to 179th in the rankings from a high of 22nd in 2009 when she also reached the quarter-finals at Wimbledon.

The bubbly German, who beat French Open champion Li Na in the second round, also suffered a health scare in Roland Garros where she was carried off on a stretcher following a second- round defeat by Vera Zvonareva.

There was nothing wrong with her on Tuesday, though, as she pummeled the tenacious Bartoli with massive serves and pounding groundstrokes to reach her first grand slam semi-final despite an attack of nerves when she served for the match at 5-4 in the second set.

"It just feels amazing to be in the semi-finals, especially after all I went through," Lisicki, who met Graf in Las Vegas last year, told reporters.

She took the opening set in 42 minutes and recovered from a break down in the second to lead 5-4 with her potent serve to come. A netted backhand cost her the first match point, she then agonizingly hit the tape with an attempted drop shot, one of the few occasions she failed with her favorite stroke.

A third match point went begging when she fired a forehand wide and a revved-up Bartoli seized her moment to break back before leveling the match in the tiebreak.

A sweat-streaked Bartoli was visibly suffering with fatigue in the decider, however, and Lisicki ruthlessly ran her around as she powered to victory.

Despite it being women's quarter-final day all the early talk around the grounds was about the state of men's defending champion Rafa Nadal's left foot which he injured in his four-hour victory over Juan Martin del Potro on Monday.

The 25-year-old Nadal practiced later on Tuesday and looked to be moving freely while knocking with a compliant junior.

"I thought I had something serious but as the match went through the pain got better and thankfully the tests don't show an injury," Nadal said.

(Reporting by Martyn Herman)