Updated

By Mark Meadows

PARIS (Reuters) - Champion Rafa Nadal cut loose after a shaky French Open start to batter Robin Soderling 6-4 6-1 7-6 and Andy Murray again tried to tie himself in knots before easily sealing his semi-final spot Wednesday.

The first and fourth seeds will meet in a stellar last four in which rampant second seed Novak Djokovic and 16-times grand slam champion Roger Federer will also lock horns Friday.

In contrast, all four top seeds in the women's game are out after Victoria Azarenka joined the list of flops by losing 7-5 6-2 to Li Na and Russian Maria Sharapova beat Andrea Petkovic 6-0 6-3 in their quarter-final.

Sharapova and Li will meet in a semi-final clash of styles Thursday after Russian elegance and Chinese determination powered them though. Champion Francesca Schiavone and France's Marion Bartoli clash in the other semi.

Five-times winner Nadal, whose only French men's singles loss was to Soderling in 2009, endured his first-five set match on the Paris clay in the first round and had only gradually improved since but he was back to best against the Swede.

"I am very happy, to play against Robin is always difficult," he said courtside.

"I played better than I have on other days. I played a very good level today and Robin maybe made more mistakes than usual."

Hitting winners from the baseline for fun, Nadal was right back at home on the Philippe Chatrier court he has made his own with Spanish flags and fans holding up banners asking for a kiss adding to the party mood.

The crowd were so boisterous that the umpire had to repeatedly calm down their Mexican waves and chants while Soderling just tried to focus on getting a ball in.

The fifth seed's troubles were summed up in the first set where he was broken straight away and although they then exchanged breaks, Soderling made a rare foray to the net only to leave a shot from the Spaniard wrongly hoping it was out.

DROP SHOT

Murray, who had battled an ankle injury and Viktor Troicki for five sets over two days in round four, had less of a stroll as he found himself 4-1 down in the first set against Juan Ignacio Chela but the battling Briton prevailed 7-6 7-5 6-2.

The world number four managed to throw away a 5-2 lead in the second but recovered to outfox the unseeded Argentine, winning with a drop shot as he reached his first French semi.

Whether it was Sharapova's yellow dress or the bright Roland Garros sun, German 15th seed Petkovic was left dazed and dazzled while Li had more of a tussle with Belarus fourth seed Azarenka.

"I don't remember the last time we played but I'm very excited to be in the semi-finals," Sharapova said when asked about her 2009 last-16 win over Li here.

Racing through the first set without any need for extravagance, Sharapova looked almost as shocked as her opponent but the second was more of a duel with the Russian's grunting contrasting markedly with her poise around court.

The former world number one sealed her progression when Petkovic netted a routine forehand on her own serve.

A slow start to the second grand slam of the season became a shrewd bid at peaking at the right time for the seventh seed once the top three seeds crashed out early.

The first Chinese to make it this far at Roland Garros, Li never gives up on any point and the Australian Open runner-up also has the backing of millions of fans back home.

The sixth seed charged back from going a break down at 2-1 by hitting every shot with all her might so Azarenka, a hot tip after her good form in the buildup, just could not dictate.

Li repeated the same trick in the second set before victory.

"This is a huge surprise for me," Li said.

(Editing by Ed Osmond)