Diego Godin scored the only goal of the game as Atletico Madrid beat Athletic Bilbao 1-0 in their first leg Copa del Rey quarter-final clash at the Vicente Calderon.
Ander Herrera could have put Bilbao ahead in the 11th minute, but the midfielder's left-footed shot from inside the area flew over the bar.
Ibai Gomez came close for the visitors in the 16th minute, as he managed to get beyond the Madrid defence before firing into the side-netting.
Iago Herrerin did well to deny Adrian Lopez in the 40th minute, after Koke had played the striker through on goal, only for Herrerin to rush off his line and make the block.
One minute later and Atletico were in front thanks to Deigo Godin's powerful header, after Koke had swung in a cross from the right flank.
Oscar De Marcos tried his luck from range in the 58th minute, but the midfielder's went wide of the target.
The crowd at the Vicente Calderon had to wait until the 83rd minute for the next bit of goal mouth action, as Mikel Rico's deflected shot went wide of the post.
The home side were happy with the lead and were in no rush to double their advantage, while Bilbao struggled to trouble Madrid in the closing stages.
The second leg of this quarter-final takes place at the San Mames Stadium next week Thursday.