Real Madrid remain on course for a third straight Champions League crown after Marcelo and Marco Asensio secured a 2-1 win at Bayern Munich.

Marco Asensio's half-time introduction proved decisive as Real Madrid pickpocketed a 2-1 win at Bayern Munich in the first leg of their Champions League semi-final.

Bayern overcame the early loss of Arjen Robben through injury to lead when Joshua Kimmich caught Kaylor Navas with a rasping finish before the half-hour mark.

Zinedine Zidane's European champions never truly recovered their defensive poise from that point, even after Marcelo clattered home a 44th-minute equaliser.

Full-backs were the heroes in both first-half goals, but an awful error by Bayern left-back Rafinha allowed Asensio, on for the struggling Isco, to hand Madrid a significant second away goal.

Cristiano Ronaldo, who had scored in every match in this season's competition, had a strike ruled out for handball – an advantage that would have further flattered Zidane's men after a strangely error-strewn encounter at the Allianz Arena, where Robert Lewandowski's pursuit of a 40th goal this season went awry in untimely fashion.