Nani heads in a Cristiano Ronaldo shot but was called offside and the goal was disallowed. Really though, what was Nani thinking, the ball was already in the net and no Spanish players were around to stop it. Portugal still won the match 4-0, so in the end the disallowed goal was meaningless, unless you're Cristiano Ronaldo.
From ESPN: And while Nani was initially admant that he was onside, the Manchester United winger admitted that, on reflection, his decision to put the ball into the net was an erroneous one.
"I touched the ball because I thought I wasn't offside," Nani said. "Everything happened so quickly. After having time to think about it I apologised to Ronaldo. It was a great piece of play and I shouldn't have ruined it.''
Ronaldo, who threw his captain's armband onto the pitch in anger after the goal was disallowed, felt the ball had already crossed the line before Nani got to it.
"I don't understand, even a blind man could see it was a goal, the ball was half a metre into the net,'' Ronaldo said in Marca. "I don't know if it's a coincidence or not but my best goals with the national team are being disallowed. I remember an overhead kick in the Bessa stadium which wasn't given."
Update: This, I believe, is the overhead kick that Cristiano was talking about that was also disallowed. Poor Ronaldo, so, so many of his great goals called back. I think he might shed a tear or two over this. This is quite a goal though, and I don't see why it was disallowed.