Our guide to what to look out for on Day 5 of the London 2012 Olympic tennis event...
Serena Williams (USA)  v Vera Zvonareva (RUS) : The at-times temperamental American against the at-times temperamental Russian. Both girls have had a tendency to let their emotions boil over on court – Zvonareva with herself, Williams taking it out on ... well, whoever’s riled her. They have split their meetings on grass, including the 2010 Wimbledon decider, but Williams won that handily. Zvonareva will do well to be at her best having battled injury and a slump in confidence.
Pick: Expect Williams to be on her game as she has to back up for doubles later.
Novak Djokovic (SRB)  v Lleyton Hewitt (AUS): When the 2011 Wimbledon champ met the 2002 Wimbledon champ in the Aussie Open this year, veteran Hewitt sent his home crowd into a frenzy when he somehow stole a set off the defending champion in his first tournament back from yet another bout of surgery. The Serbian was in the zone against another veteran with an affinity for the grass-courts, Andy Roddick, yesterday and should dish out more of the same today. Hewitt will give every ounce and then some in what will likely be his Olympic singles farewell.
Pick: Hewitt to sneak a set before falling in three.
Andy Murray (GBR)  v Marcos Baghdatis (CYP): Muzz is going all out for an Olympic medal on home soil at these Games, making his mixed double debut later in the day. Stifling a flashy Cypriot is his only concern though, at this stage. The draw has opened up nicely for the Brit. Spanish claycourter, 11th seed Nicolas Almagro is the only seed he could meet before the semi-finals. Too soon to call medal play-offs? Baggy digs seeing big white Cypriot flags waving in the crowd and will do his best to rattle Murray.
Pick: The crowd to ride every point as Muzz grimaces and fist pumps his way through in two high-quality sets.
Roger Federer (SUI)  v Denis Istomin (UZB): Federer was brutal against a Frenchman who was expected to test him last round. The big Uzbekistani is not expected to test him and while he’ll play with nothing to lose, his upset over Spanish 14th seed Fernando Verdasco is the last one he’ll be causing at these Olympics.
Pick: Federer comfortably.
Victoria Azarenka (BLR)  v Nadia Petrova (RUS) : On paper Vika’s now expected to win two gold medals after being announced top seed with big Max Mirnyi in the mixed. With the bookies though, she won’t be favourite to win either, although a quick-fire second round win yesterday has gone a long way to quashing concerns over her shaky opening form. Petrova has Olympic pedigree on her side. Her mum won a 400m relay bronze at the ’76 Games and her dad was a top hammer thrower. When she’s fit and firing she can do some serious damage.
Pick: Azarenka to dig deep to deny an inspired Petrova.
Others to watch:
Maria Sharapova (RUS)  v Sabine Lisicki (GER) : Same round, same surface, same court. It’s a rematch of their Wimbledon clash from a few weeks ago. The German's looking to spring the upset again.
David Ferrer (ESP)  v Kei Nishikori (JPN) : The dogged David Ferrer is flying under the radar as he always does. Unlikely Nishikori will clip those wings.
Mixed doubles first round: The likes of Murray, del Potro, Azarenka and Stosur shift their focus from singles to mixed later this afternoon.