Atletico Madrid's Koke is in action with Real Madrid's Cristiano Ronaldo during their Champions League Quarter Final First Leg match at Vicente Calderon in Madrid, April 14, 2015. [Photo/Agencies]

Madrid could have opened the scoring after a free kick in the second minute but Oblak stopped Dani Carvajal's shot.

Two minutes later, Oblak blocked Gareth Bale's effort after Atletico defender Diego Godin had failed to make a clearance, and the Atletico keeper followed up by saving Cristiano Ronaldo's free kick shortly afterward.

Oblak made a spectacular diving save to stop another shot by Bale in the 31st and, after denying both James Rodriguez and Luka Modric before the break, was also kept busy in the second half.

Atletico came out with renewed attacking energy after one of coach Diego Simeone's renowned halftime pep-talks, and midfielder Arda Turan missed a chance when he headed just wide of the near post in the 49th.