By Kamakshi Tandon

V. Williams (USA) [23] vs. M. Sharapova (RUS) [2]Centre Court – 3rd match

The big question is, whose serve will show up? It could well decide the match. Sharapova’s shoulder troubles have clearly had an effect on her serving in recent months, but the stroke has been fairly solid during Wimbledon. Venus, meanwhile, had 14 double faults in her last match and struggled with her first serve at some crucial moments – but had nine aces and a 124 mph serve during her second-round win. It doesn’t exactly spell consistency.

These two last played in Miami – a tight match in more ways than one. Sharapova edged that contest 7-5 in the third after some very erratic play from both players. Their last match at Wimbledon two years ago was won in fairly straightforward fashion by Venus, but Sharapova says she’s a different player now.

“I felt like at that stage in my career I wasn't really ready. She played really good tennis. I didn't think that I was capable of playing the same tennis for two or three sets,” said Sharapova. “That's something that I've improved.”

She’ll have to prove it against Venus, who was fired up after her come-from-behind win on Monday and has her competitive juices flowing. If Sharapova plays a solid, even match, she should get enough erratic moments from Venus to come through. But expect a fight.

Prediction: Sharapova

N. Vaidisova (CZE) [14] vs. A. Mauresmo (FRA) [4]Centre Court – 11:00 am

These two played twice last year – both times they went to three sets, and both times Vaidisova won. So the 18-year-old Czech should feel good about her chances, and if she has a great serving day, might pull off her third straight win.

But barring that possibility, Mauresmo’s variety and ease on grass gives her an edge on this surface and she’s feeling good about her performances so far. Vaidisova will also be coming in without any rest, which shouldn’t be a physical factor but might be a mental one.

Prediction: Mauresmo

A. Ivanovic (SRB) [6] vs. N. Petrova (RUS) [11]Court 2 – 11:00 am

The moody Russian seems happy with her career choice again, just a few weeks after saying she was toying with the idea of quitting. Ivanovic, meanwhile, seems to have bounced back nicely from the emotions of her French Open run and produced three solid wins to set up this meeting.

This is a tough one to call, but if things get close, Ivanovic is more likely to stay positive.

Prediction: Ivanovic

Day 8 picks still active:

Andy Roddick (USA)[3] v. Paul-Henri Mathieu (FRA)

Roddick can expect to be tested by the talented Frenchman, but should come through if his serve keeps firing the way it did during his first two matches. Though he struggled more during his last match against Fernando Verdasco, he managed to finish things off in straight sets thanks to a couple of good tiebreak performances.

Roddick has extra motivation for wanting to keep things quick – potential semifinal opponent Roger Federer was handed a walkover into the quarterfinals by Tommy Haas.

Mathieu has never quite lived up to the potential he displayed in taking Andre Agassi to five sets at the French Open in 2002 and accusations of mental weakness have dogged him ever since he nosedived following a tough Davis Cup loss later that year.

Roddick has lost their only ATP meeting but thinks his experience on the big stages will give him an advantage. “This is different territory,” said Roddick. "It's the fourth round of a Grand Slam. I don't think he's ever been to the quarters. Mentally I feel like I have a bit of an edge going in.”

Prediction: Roddick

Richard Gasquet (FRA)[12] v. Jo-Wilfried Tsonga (FRA)

The second quarter of the men’s draw was packed with Frenchmen, and these are the two who have survived. That’s no surprise to Gasquet – he said that as soon as he saw Tsonga win his first round match against compatriot Julien Benneteau, he knew he would be facing him in the fourth round. If Tsonga stays uninjured, added Gasquet, a Top 20 spot by the end of the year is a real possibility.

The two have never played each other on the ATP tour, but go way back as youngsters playing in France. Tsonga has certainly justified the wildcard given to him after his upset of Lleyton Hewitt at Queen’s, and has now won 34 of his last 36 matches. After two years of back problems, he seems to be on track again.

Can he keep his run going for one more round? Gasquet still has the slight edge, but if he doesn’t come out looking to take the match to Tsonga, he could find himself getting pushed back by Tsonga’s free-wheeling shots and watching winners go by.

Prediction: Tsonga

Anastasia Pavlyuchenkova (RUS)[1]  v.  Michelle Larcher de Brito (POR)

A juniors match that could be a marquee main draw match in a few years’ time. Fourteen-year-old Larcher de Brito made a splash by defeating Meghann Shaughnessy in the first round of Miami this year, and 16-year-old Pavlyuchenkova is the reigning junior US Open and Australian Open champion.

Pavlyuchenkova won just one game against Hantuchova in the main draw, but will be hoping to do a little better amongst her own age group.

Prediction: Pavlyuchenkova

Day 6 picks still active:

R. Soderling (SWE) [28] vs. R. Nadal (ESP) [2]

The Swede is a tough opponent on fast surfaces and will test Nadal, but actually winning the match will be a tough proposition. Nevertheless, expect a rainy, slick court tomorrow which could add to Nadal’s challenges.

The Spaniard was unhappy with the windy conditions during his last match but has otherwise pronounced himself comfortable on the grasscourts. He also says they’re playing the same as last year, when he reached the final.

Prediction: Nadal

L. Hewitt (AUS) [16] vs. G. Canas (ARG) [22]

This one could take a while. It’s no surprise to see former champ Lleyton Hewitt building on some encouraging results during the clay season to reach the second week here for the fourth year in a row. Canas' presence wasn’t quite as expected – he had a mediocre clay season after defeating Federer twice in a row during the early part of the year. Still, he has reached the fourth round here before and won’t be a pushover.

If Hewitt gets sucked into long rallies and doesn’t look for ways to take the initiative, he could find himself in trouble. But if he serves as well as he did in his last match and gets into a good rhythm when returning, he should wriggle through.

Prediction: Hewitt