The decibel level went up a notch at Wimbledon [Images] on Tuesday as defending champion Maria Sharapova [Images] moved ominously into the semi-finals.

After four rounds of gentle sparring, the 18-year-old Russian was given a real battle early on by compatriot Nadia Petrova on Court One before emerging victorious 7-6, 6-3.

"It was a tough match ... it sends shivers down my body to be in the semi-finals again," she said, after securing a last four showdown with a revitalised Venus Williams [Images] who held off a stirring Mary Pierce comeback to win 6-0, 7-6.

While Sharapova's thunderbolts were accompanied by a cacophony of ear-splitting yelps, it was the low rumbling of world number one Lindsay Davenport's [Images] seismic forehand that echoed round Court One later.

The top seed carried on where she left off against Kim Clijsters [Images] in the fourth round to out-gun Russian fifth seed Svetlana Kuznetsova [Images] 7-6, 6-3.

"It was important for me to consolidate the great win I had yesterday, I thought I handled it pretty well," said 1999 champion Davenport, who now has third seed Amelie Mauresmo in her sights after the Frenchwoman glided past battle-weary Russian Anastasia Myskina [Images] 6-3, 6-4.

Of the four Russians that reached the quarter-finals, only the Florida-based Sharapova is still in the hunt.

"She has a big game, she is a great fighter, we'll just have to go out and battle," said Sharapova of twice former champion Venus who has never lost a semi-final at Wimbledon.

Sharapova has become a worldwide brand since her stunning triumph against Serena Williams [Images] in last year's final -- she has just launched her own perfume and strides the grass in gold-encrusted tennis shoes.

When she walks out on court, however, the multi-million dollar smile is replaced by the ice-cold stare of an assassin.

Petrova, five years older than Sharapova, was not intimidated, matching the queen of grasscourts blow for blow in the first 12 games to force a tiebreak.

The bristling Sharapova thrives on pressure, however, and displaying the sheer bloody-mindedness that is as much a weapon as her sizzling groundstrokes, she moved into a 6-4 lead.

Petrova saved both set points but Sharapova made no mistake at 7-6, hammering an unstoppable forehand past the eighth seed.

She hurtled into a 3-0 lead in the second set and even when Petrova threatened to break back at 3-5, Sharapova was blessed with two lucky net cords as she closed out the match.

"I thanked the fairy for taking the ball and bringing it over the net," Sharapova said.

Venus, relegated to 14th seed this year, looked like the player who won consecutive Wimbledon titles in 2000 and 2001 as she pulverised Pierce in the first set.

The 30-year-old Pierce came to her senses in the second set and even had five set points in a dramatic tiebreak before Venus edged it 12-10 on her second match point.

"She was hitting winners out of nowhere," said Venus.

"She didn't give me an inch in the second set so I had to take as much I could," added the relieved American.

LEAN AND MEAN

Davenport, 29, appeared on the verge of retiring this time last year when she lost in the last four to Sharapova. Fit, lean and mean, she now looks the biggest threat to the Russian.

Kuznetsova, who beat Davenport in the semi-finals of the US Open [Images] last year, has the game to write her name on the Wimbledon roll of honour but never really threatened after losing the first set tiebreak.

"There's no question that physically I'm a better athlete and I believe a smarter player than I was in the late Nineties," said the Californian Davenport, who is certain to keep her top ranking whatever happens between now and Sunday.

Davenport holds an 8-3 career lead over Mauresmo, although the Frenchwoman has not dropped a set this year, fuelling the belief that she can win a long overdue Grand Slam title.

The 25-year-old was at her balletic best against the feisty Myskina as she skipped into the semi-finals for the third time in her past three visits.

"Maybe I'll make it one step further this year," said Mauresmo. "I really wanted to be aggressive in this match and that's what I did from the first point."

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