Brahim Diaz scored a brilliant winner to give Real Madrid a slender advantage over city rivals Atletico after the first leg of their Champions League last-16 tie.
Rodrygo put the hosts ahead inside four minutes in the Bernabeu when he sprinted past Javi Galan and chopped inside before bending a wonderful hit past Jan Oblak.
Atletico, though, quickly settled into the game and levelled in the 32nd minute with another wonderful goal.
The in-form Julian Alvarez picked up the ball on the left side of the box, wrongfooted Eduardo Camavinga and whipped a spectacular curling strike around Thibaut Courtois and in off the post.
It was the Argentine striker’s seventh goal in nine appearances in the competition.
But it was Diaz, another former Manchester City player, who claimed the decisive goal in an electric Madrid derby.
The Spaniard sent Atletico defender Jose Gimenez to the floor as he skilfully waltzed into the box before driving a low shot into the far corner in the 55th minute.
The 25-year-old midfielder had stepped up in Jude Bellingham’s absence, with the England international serving a one-game suspension after picking up his his third yellow card in the competition against Manchester City earlier this month.
Bellingham will be available for the defending champions when they make the short trop to the Riyadh Air Metropolitano for the return leg on Wednesday, 12 March (20:00 GMT).
