Atletico beats Bilbao 2-0 to stay within 7 points of Barca
Atletico will visit Barcelona on March 4 in what could be its last chance to inject some drama into the title race.
''We will have many important matches after (the game at Barcelona) but this is our path forward, being prepared. We have a competitive team,'' Atletico coach Diego Simeone said.
Madrid remained in a distant fourth place after outgunning Real Betis 5-3 in Seville, four days after it won the first leg of its Champions League last-16 match with Paris Saint-Germain.
Atletico's win over Bilbao was textbook Simeone: an ironclad defense and just enough from its attack to take the three points.
Simeone's side suffocated Bilbao, which never threatened goalkeeper Jan Oblak. The hosts, who have conceded a league-low nine goals, recorded their 16th clean sheet through 24 rounds.
Gameiro broke the deadlock at Wanda Metropolitano Stadium shortly after replacing Jorge ''Koke'' Resurreccion in the 59th. The forward scored from a pass by Antoine Griezmann after Saul Niguez had recovered the ball in midfield to spring an attack that caught Bilbao in disarray.
Costa sealed the result with 10 minutes left when Bilbao defender Unai Nunez failed to intercept a pass by Gameiro, leaving the Spain striker all alone to fire past goalkeeper Kepa Arrizabalaga.
''It was a good day for us. We worked hard and scored two goals,'' Gameiro said. ''We don't stop, we are playing well and are going to enjoy this.''
Atletico has won four straight in the league and started its Europa League campaign on Thursday with a 4-1 victory at Copenhagen.
Marco Asensio continued to impress as the 22-year-old forward scored twice to help Madrid tame Betis.
Asensio headed in after Cristiano Ronaldo's strike was parried by Betis goalkeeper Antonio Adan in the 11th.
Betis pressed Madrid back into its area and Aissa Mandi headed in Joaquin Sanchez's pass to equalize. A counterattack led by Sanchez ended with a shot by Junior Firpo that Madrid defender Nacho Fernandez put into his own net to give Betis a 2-1 lead before halftime.
But Madrid picked Betis apart after Sergio Ramos scored with a header from a corner in the 51st. Dani Carvajal set up Asensio for his second after an inspired run before Ronaldo blasted a fourth goal past Adan in the 65th for 4-2.
Betis wasn't through and Firpo crossed for Sergio Leon to score with five minutes remaining, only for late substitute Karim Benzema to finish off Betis in stoppage time.
Madrid lost left back Marcelo to a right leg injury in the first half. Madrid has its return leg at PSG in the Champions League round-of-16 on March 6.
''We know the talent they have and they played well, so we can be happy with the win,'' Madrid coach Zinedine Zidane said. ''We started well in the first 10 minutes and then we let our guard down as we do sometimes. But we responded, and responded well.''
Madrid remained 17 points adrift of Barcelona.
Espanyol had three back-to-back chances in the final seconds of the match but failed to score a winner in a 1-1 draw with Villarreal.
Villarreal went ahead through Rodrigo Hernandez's first-half goal and dominated the match in Barcelona until Esteban Granero dipped a free kick over the wall to equalize in the 85th.
Espanyol's Leo Baptistao then hit the bar in stoppage time, with two teammates following up with attempts that almost snatched victory before the final whistle.
ON THE BRINK
Levante's winless streak reached 12 straight rounds after a 3-0 defeat at Real Sociedad.
Levante remained on the brink of the relegation zone at two points above Las Palmas, the first of three teams in danger of the drop.