But Barcelona equalised in the second half through Alexia Putellas' penalty.

Claudia Pina then swept in with eight minutes left before Putellas clipped in a third in the final seconds.

It was heartbreak for Real, who had looked for a long while like they were going to stun their opponents in El Clasico - the first time it has taken place in the Champions League.

Real have never beaten Barcelona but the turning point was the penalty decision, with the referee awarding a spot-kick eight minutes into the second half after a check by the Video Assistant Referee for a foul by Carmona on Caroline Graham Hansen.

From then on Barcelona dominated as they looked to find a winner, with Pina firing over from a good position and Jennifer Hermoso heading wide.

The second duly arrived when Aitana Bonmati's shot was blocked but Pina was on hand to sweep in and Putellas then ensured Barcelona left Madrid with a healthy advantage.

The two sides will meet at Barcelona's Nou Camp stadium for the return leg on 30 March and that game is set to be an incredible occasion, with more than 70,000 tickets sold.

The winner of this tie will play either Arsenal - the only English side left in the competition - or Wolfsburg for a place in the final.