Atletico Madrid cut the gap behind Barcelona to nine points in La Liga after Kevin Gameiro's penalty sealed a 1-0 win over Deportivo La Coruna on Sunday.
Barca's 2-2 draw at Sevilla on Saturday gave Atletico a rare chance to reduce the Catalans' lead at the top, which they took with a hard-fought victory at the Wanda Metropolitano.
Gameiro made no mistake from the spot in the 34th minute after referee Daniel Trujillo adjudged Atletico's Saul had been pulled down by Pedro Mosquera.
While Diego Simeone's men still require a Barcelona collapse with only eight games left, Deportivo are also in need of a miracle to avoid relegation. They remain 19th and eight points adrift of safety.
Elsewhere on Sunday, Valencia took one step closer to Champions League qualification after Spanish World Cup hopeful Rodrigo Moreno scored in a 1-0 win over Leganes.
Their victory became even more valuable after Villarreal slipped to a 1-0 defeat by Malaga, giving Valencia a 15-point cushion in fourth place. Gonzalo Castro was the match-winner for Malaga, with a first-half penalty.
Espanyol and Alaves played out a 0-0 draw while Eibar were also held to a stalemate by Real Sociedad.