Japan stunned two-time champions South Africa to cause arguably the biggest upset in rugby union history.Karne Hesketh crossed in the final minute to win an incredible World Cup Pool B encounter in Brighton.South Africa led 12-10 after Francois Louw and Bismark du Plessis tries.Lood de Jager and Adriaan Strauss also scored for the Springboks, but Ayumu Goromaru contributed 24 points, including a try, before Hesketh`s dramatic clincher.Japan had not won a World Cup game since 1991, while South Africa were world champions in both 1995 and 2007.Score:South Africa (12) 32Tries: Louw, Du Plessis, De Jager, Strauss Cons: Lambie 2, Pollard Pens: Lambie, PollardJapan (10) 34Tries: Leitch, Goromaru, Hesketh Cons: Goromaru 2 Pens: Goromaru 5