Sharapova determined not to be intimidated by the power of Serena as she seeks a repeat of historic singles win

The Russian was 17 when she thrashed Williams 6-1 6-4 to land her first grand slam, and the result was hailed at the time by Martina Navratilova as "the best thing" that could have happened to the women's game.

At the time, the Williams sisters were the dominant force in the game, closely followed by the Belgian pair of Justine Henin and Kim Clijsters.

Six years on and little has changed in that respect.

Sharapova has won two more slams, at the US Open in 2006 and Australian Open in 2008. But for injuries, she might have had more, and a fourth may not be far away. However, few have tipped her for Wimbledon glory this year.

Shoulder trouble has been her most recent problem, but the 23-year-old Sharapova has shown outstanding form so far in these Championships and should ask more questions of defending champion Williams than the American's three opening opponents.

So far, Williams has won each first set 6-0. Her phenomenal force on the court has blown away opponents but Sharapova should be able to live with it better than Michelle Larcher De Brito, Anna Chakvetadze and Dominika Cibulkova have managed.

"Tennis is obviously not just about power," said Sharapova. "I think on grass it's a big key to the game. But I don't think that's everything in tennis."

Finesse and teenage appetite won out six years ago, but Sharapova also hits the ball more heavily than most so should not be smashed off court.

She remembers well the match which made her an overnight superstar, but insists it will have no bearing on the outcome today.

"I think that was our last meeting on grass," said Sharapova. "It's tough to take anything away from that match as it was many years ago. This will be a new day. I don't really think about yesterday or the day before.

"Whoever I play when I go out there, it's a new match. You have to take it as a new day.

"There are always wonderful memories. But when you step out on the court, it's new. You've got to start from scratch. The score is 0-0."

If the incredible happens and Williams wins another first set by a whitewash, she will know what to expect in the next, and has taken on board the suggestions of a legend in how to combat the reaction.

"I was talking to Billie Jean (King) in the locker room," said Williams, 28.

"She said when a player wins 6-0 over your opponent, you've got to expect them to really come out loose, like they have absolutely nothing to lose, just start going for shots.

"I think that was really good advice. So if that happens again, I'll be ready."

Like Sharapova, Williams will not be looking back to 2004 when she determines how to tackle her opponent but she suggests the defeat that day was shaped in her mind.

"I just remember I was really nervous," said Williams. "I think I put too much pressure on myself. It didn't work out. That was that."

While both Sharapova and Williams know how Wimbledon triumph feels, neither Clijsters nor Henin have had the privilege.

Today they play it out for a place in the quarter-finals, the draw having been cruel in the first full year of their comebacks from retirement by putting them on an early collision course.

Henin has been runner-up twice, to Venus Williams in 2001 and Amelie Mauresmo in 2006, and Clijsters has won two US Opens and reached finals of the French and Australian slams but has yet to experience a Wimbledon final.

"I have to be very aggressive if I want to have a chance," said Henin. "I know what I'll have to do. But it's not that easy to do it on the court."

With many expecting a classic, Henin pointed out: "I would say in our first career, we've never played our best tennis against each other."

With Serena at the top of the draw, five-time champion Venus Williams is in the bottom half, along with Clijsters and Henin.

Venus faces Jarmila Groth, the Slovakian-born player who married Australian player Sam Groth and gained Australian citizenship last year.

Unseeded Groth has not dropped a set and she knocked out American seed Melanie Oudin in the second round.

Venus said: "I played her before when she had a different last name. It's been a while. But I know that she definitely likes to go out there and hit the ball hard."