Japan scored one of the greatest upsets in Olympic football history Thursday after stunning reigning world and European champions Spain 1-0 at Hampden Park. A first-half goal from Yuki Otsu secured a famous victory for Japan that revived memories of their famous Olympic upset of mighty Brazil at the 1996 Games in Atlanta. With a young side bolstered by the likes of Jordi Alba and Juan Mata, both members of Spain’s victorious Euro 2012 squad, the Spanish had been expected to collect a straightforward three points in their opening Group D game. However despite dominating possession 65 percent to 35 percent the Spaniards were rocked back by the ferocity of Japan’s play throughout, and the Asians were well worth their victory. Spain were left reeling on 34 minutes when Japan punished slack defending from a corner to score through Otsu. Takahiro Ohgihara swung in an inviting corner from the right and Otsu managed to get goalside of Martin Montoya to jab a low shot past the stranded Manchester United goalkeeper David De Gea.