Our guide to what to look out for on Day 6 of the London 2012 Olympic tennis event...
Jo-Wilfried Tsonga (FRA)  v Novak Djokovic (SRB) : Jo had a busy day at work yesterday backing up to win a singles and doubles match after his four-hour marathon the night before. Novak had a tough time getting past Hewitt too and while both have dropped sets in two of their three matches, the Serbian will start the fresher of the two. Djokovic leads the head-to-head 6-5 but hasn’t lost to the Frenchman since the Australian Open two years ago.
Pick: Djokovic in three.
Roger Federer (SUI)  v John Isner (USA) : This is it now for Rog after bombing out in the doubles yesterday. If he’s going to win gold at London 2012 it will have to be in singles. Revenge is on the cards here after the Swiss king lost on home soil in a Davis Cup tie this year to the towering American. Isner’s best chance is in tie-breakers.
Pick: Federer won’t lose twice this year in a SUI v USA match.
Kim Clijsters (BEL) v Maria Sharapova (RUS) : The sentimental favourite Clijsters will have the crowd on her side in her first Centre Court match of these Olympics. Sharapova was fiercely determined in her struggle with Lisicki yesterday and looks to be the sharper of the two. Both deserve an Olympic medal in their trophy cabinets at the end of their careers but the Belgian may just be denied the honour.
Pick: Sharapova to storm home in three.
Andy Murray (GBR)  v Nicolas Almagro (ESP) : Murray lifted his game to pass what should end up being his toughest test before the semi-finals against Baghdatis yesterday. If the turf on Wimbledon’s No.1 Court were covered in red dirt the big-hitting Spaniard would be in with a shot. Not on grass.
Pick: Murray into medal contention in two.
Others to watch:
Victoria Azarenka (BLR)  v Angelique Kerber (GER) : Kerber ended Venus’s singles run before falling to Vika in mixed doubles yesterday. Expect the Belarusian to make it two from two.
Serena Williams (USA)  v Caroline Wozniacki (DEN) : Serena has lost to Wozniacki just once. On grass, it favours Serena even more. Given Caro’s ongoing form slump it favours Serena even more.
Juan Martin del Potro (ARG)  v Kei Nishikori (JPN) : JMdP has never lost a set to the little man from Japan. Can look forward to a semi-final tussle with Rog.
Petra Kvitova (CZE)  v Maria Kirilenko (RUS) : Petra’s finding form slugging it out on the back courts. What’s the girl gotta do to get a match on the big courts? Reach the medal play-offs.