Atletico Madrid moved to within nine points of LaLiga leaders Barcelona with a 1-0 win over Deportivo La Coruna on Sunday.
With Antoine Griezmann suspended and Diego Costa restricted to a second-half appearance from the bench, it was Kevin Gameiro who struck the only goal of the game to keep his side's faint title hopes alive.
Barca snatched a point against Sevilla on Saturday thanks to a dramatic late comeback, but the result was enough to give Atleti some hope of keeping the title race going with eight matches left to play.
They struggled to break down Depor in the capital until Gameiro swept home from 12 yards after Saul Niguez won a rather soft spot-kick, following which the result never truly looked in doubt.
The win, Atleti's 12th in a row at home to Depor in LaLiga, means they are almost certain of a Champions League spot and permits some optimism about hauling in Barca in the final few weeks.
The visitors, however, remain second-bottom after a club-record 15th league match without a win, making for an unhappy 42nd birthday for head coach Clarence Seedorf.
Atleti struggled to fashion clear chances despite early dominance of the ball, and Jan Oblak, making his 150th appearance for the club, was forced to make a good save with his foot to prevent Lucas Perez breaking the deadlock on the counter-attack.
The Arsenal loanee threatened again with a header but Depor's encouraging start was undone 32 minutes in, when referee Daniel Jesus Trujillo Suarez awarded a penalty for a slight shirt pull on Saul by Pedro Mosquera. Gameiro promptly sent Ruben Martinez the wrong way from the spot.
Mosquera missed a good chance to make amends before the break, nodding Sidnei's cross over the bar with the goal at his mercy, but Depor were simply not offering enough of a threat against an Atleti defence that included 19-year-old debutant Carlos Isaac at full-back.
The home side remained comfortable in the early stages of the second half, despite rarely looking like adding a second goal, aside from a Saul effort that deflected off the outside of the right-hand post.
Simeone responded by bringing on Costa for Carlos Isaac and the striker almost made an immediate impact, curling a shot just wide from the edge of the penalty area.
Depor substitute Borja Valle used the Atleti right flank to spring a counter-attack and race clean through on goal, only for Lucas Hernandez to make a superb sliding challenge to deny an almost certain goal and earn a celebratory chorus from the Wanda Metropolitano crowd.
Fernando Torres tested Ruben from distance but that was as close to a second goal as Atleti went, as they now turn their attention to Thursday's Europa League quarter-final first leg against Sporting CP.
