Holders Real Madrid staged a dramatic late comeback, including a 94th-minute winner, to beat Sporting Lisbon 2-1 in their Champions League opener.
Sporting took the lead through a low shot from Bruno Cesar but Cristiano Ronaldo equalised in the 89th minute with a superb long-range free-kick.
And Alvaro Morata - back at Real after two years with Juventus - won it with a stoppage-time header.