LONDON, England - With the Olympic Tennis Event reaching the quarterfinal stage, a medal is now within touching distance for all those left in the draw. Among their number is Angelique Kerber, who took out Sydney gold medalist Venus Williams in the last round and now faces World No.1 Victoria Azarenka in Thursday's standout encounter.

Thursday, Quarterfinals
Centre Court
[1] Victoria Azarenka (BLR #1) vs. [7] Angelique Kerber (GER #7)
Head-to-head: Azarenka leads 1-0
After breezing through her opening two matches, Angelique Kerber was probably looking for a slightly sterner test in the third round. She got one, and then some, against Venus Williams, who pushed her all the way in the tightest of two-setters.

Her next foe, Victoria Azarenka, was given a similarly thorough examination at the same stage against big-serving Nadia Petrova, leaving both players match toughened for their quarterfinal.

Their only previous encounter came earlier this year in Indian Wells, where Azarenka triumphed in the semifinals. This result, and her greater experience at the business end of major tournaments, gives Azarenka the slight psychological edge, although Kerber's recent form on grass makes her the most live of underdogs.

Kim Clijsters (BEL #36) vs. [3] Maria Sharapova (RUS #3)
Head-to-head: Clijsters leads 5-3
Whilst talking to the press after her third round defeat at the hands of Kim Clijsters, Ana Ivanovic suggested it would be a fitting end to the Belgian's career if she went on to win gold. In her press conference a few hours later, Maria Sharapova politely disagreed.

There are few players in the modern game with a greater will to win than Sharapova. And this will was evident for all to see in the last round against Sabine Lisicki as, a set and break down, Sharapova snatched victory from the gnashing jaws of defeat.

She will have to up her level if she is to see off Clijsters, though. In the opening three rounds the Belgian has looked in superlative form and is yet to drop a set. The two have faced one another eight times, and while the edge here lies with Clijsters, the most recent of these encounters came back in 2010.

Court 1
[4] Serena Williams (USA #4) vs. [8] Caroline Wozniacki (DEN #8)
Head-to-head: Williams leads 4-1
Serena Williams sent out a warning shot to the rest of the draw on Wednesday when she dismissed former World No.2 Vera Zvonareva in the third round for the loss of just one game. Next in the firing line is Caroline Wozniacki.

As impressive as Williams was, though, Wozniacki is unlikely to be intimidated. Indeed, the last two times the pair have met on tour, the Dane has more than held her own, triumphing in Miami before losing a three-setter a few weeks later in Madrid.

In a classic battle of aggressor against counterpuncher, Wozniacki's defensive game will have to be at its very best to halt a rampaging Williams, who has won 31 of her last 32 matches - and four titles - since the aforementioned loss in Miami.

Around the grounds…
The final quarterfinal sees 2011 Wimbledon champion Petra Kvitova take on the in-form Maria Kirilenko, while in the doubles, Serena and Venus Williams continue their quest for a third Olympic gold against No.2 seeds Sara Errani and Roberta Vinci.