Japan upset Spain 1-0 on the first day of the men's Olympic soccer tournament Thursday, while Brazil held on for a 3-2 victory over Egypt and host Britain had to settle for a 1-1 draw with Senegal.Uruguay and Belarus also won as the tournament got under way with eight matches the day before the opening ceremony. Japan pulled off the surprising win after outplaying gold-medal favorite Spain, which went a man down in the first half and couldn't fight back.Brazil got three first-half goals but nearly squandered the lead in the second, escaping with the victory to begin its quest for its first gold in soccer.Federer returnsRoger Federer is back at Wimbledon a few weeks after winning his seventh title there, bidding for the one major accolade that has eluded him: an Olympic gold medal in singles. Serena Williams has the same goal in mind.Federer plays Colombian Alejandro Falla in the first round while former No. 1 Jelena Jankovic awaits Williams in her opener.The draw was held Thursday, two days ahead of the event.Briefly Romanian gymnastics: The European champions' chances of contending for the gold medal in women's gymnastics were seriously damaged when Larisa Iordache developed plantar fasciitis in her left heel. The 16-year-old may not be able to compete in all four events in London. Greek tests positive: The father and coach of world indoor high jump champion Dimitris Chondrokoukis said his son has tested positive for stanozolol and has withdrawn from the Olympics. Kyriakos Chondrokoukis said his son has not taken any banned substance and has asked for the backup "B" sample to be tested. British cycling: David Millar, who served a two-year doping ban, was praised by the sport's top official as a model for riders who face doping allegations. International Cycling Union President Pat McQuaid said it is "very annoying and very frustrating" when riders make excuses after being caught. Millar completed his ban in 2006, then campaigned for clean cycling.