Despite having the opportunity to overtake city rivals Atletico Madrid if they secure all three points on Wednesday night, Zinedine Zidane fielded a much weaker side at the Pizjuan.
The team looked lethargic early on and were punished in the 26th minute by a Sevilla team keen to show they are better than their 5-0 Copa del Rey thrashing suggests.
Running onto a flick-on from team-mate Luis Muriel, Ben Yedder beat his marker to the ball and charged toward the goal.
The forward finished off the move by calmly slotting under Kika Casilla to break the deadlock.