Atletico Madrid edged Athletic Bilbao 1-0 at home to take a slim lead from the first leg of their Copa del Rey quarterfinal on Thursday.
After Bilbao's Ander Herrera missed a good chance to strike first, Atletico midfielder Jorge "Koke" Resurreccion swung in a cross from the right side for Diego Godin to thump home with a powerful header in the 41st minute.
The defending champions pressed to extend their advantage, but Bilbao limited them to a glancing header from Raul Garcia that goalkeeper Iago Herrerin stretched to save 10 minutes from time.
"I was lucky enough to hang a ball up there that Godin put in," Koke said. "With 1-0 the tie isn't decided, but we got a good result heading there."
Diego Simeone's side remained unbeaten at its Vicente Calderon Stadium in 18 games this season.
While his team continues to deploy the toughest defence in Spain, Atletico striker Diego Costa came up empty for a fifth match in 2014.
"The truth is that we would have liked to have at least drawn. Now we have to turn it around at San Mames," said Bilbao defender Aymeric Laporte, who tussled with Diego Costa throughout the intense match.
In other opening legs this week, Barcelona rolled to a 4-1 victory at Levante, Real Madrid won 1-0 at Espanyol, and Real Sociedad beat third-tier Racing Santander 3-1 at home.
The second legs will be next week after the 21st round of the Spanish league.