Second-half goals from Inaki Williams and Kenan Kodro hampered Atletico Madrid's LaLiga title aspirations and boosted Barcelona's bid.
Atletico Madrid rounded off a miserable week with a 2-0 loss to Athletic Bilbao as Inaki Williams and substitute Kenan Kodro struck in the second half, boosting LaLiga leaders Barcelona's title bid.
Diego Simeone's side were dumped out of the Champions League at the last-16 stage by Juventus on Tuesday, despite winning the first leg 2-0, and they fell to a second successive defeat at San Mames, meaning Barca will go 10 points clear with victory over Real Betis on Sunday.
Atleti struggled in front of goal throughout the match but felt they should have had a penalty prior to going behind when Mikel San Jose thwarted Alvaro Morata, though nothing was given.
Jose Gimenez failed to clear his lines with 17 minutes remaining, allowing Williams to steer in substitute Inigo Cordoba's cross, with Kodro completing the win just 27 seconds after coming on in the 85th minute.
Atleti failed to muster even a shot across the opening 45 minutes and only Jan Oblak's athleticism kept Ibai Gomez out 10 minutes before the break.
Antoine Griezmann dribbled into the box with purpose prior to half-time, yet Yeray Alvarez timed his tackle to perfection despite the Frenchman claiming for a penalty.
It seemed as though the visitors might need a spot-kick to find a way through but referee Santiago Jaime Latre again ignored their pleas early in the second half.
Morata tried to fire in a right-footed attempt at goal but kicked San Jose's foot before either player could reach the ball, with the official deeming Athletic's midfielder was not guilty of a foul.
Athletic went ahead after Gimenez lost possession under pressure from Cordoba, who collected Raul Garcia's pass and delivered a low cross for Williams to tap in.
The hosts struck again with five minutes to go, Gimenez's sliding challenge only serving to help Kodro's effort over Oblak and into the net.
Atletico's miserable outing was summed up when Morata blazed over a simple chance from inside the six-yard box, while Thomas Partey was denied a long-range consolation by Iago Herrerin.
What does it mean? Barca firmly on course to retain their title
Atletico could have closed the gap to Barca to four points ahead of the reigning champions' clash with Betis, but Ernesto Valverde's side could now enter the international break 10 points clear with 10 games to play.
With Zinedine Zidane leading Real Madrid to a 2-0 win over Celta Vigo earlier on Saturday, Simeone's men will now be primarily focused on keeping their neighbours – who are just two points behind them – at bay.
Cordoba and Kodro make impacts from the bench
It took under two minutes for Cordoba to make his mark on this dull encounter. Brought on for Iker Muniain, he hounded Gimenez, forcing him to lose the ball, then delivered a perfect cross to leave Williams with a simple finish. Kodro's impact was even swifter, the Bosnia-Herzegovina international scoring his maiden goal for the club with his first involvement in the match.
Gimenez all at sea at the back
Atleti's blunted attack should attract plenty of criticism but you do not expect to see Simeone's side undone with such ease at the back. Gimenez failed to deal with a routine situation that led to the opening goal, and his desperate attempt to stop Kodro adding a second was unsuccessful too.
- Athletic Bilbao have won a LaLiga game against Atletico Madrid for the first time since January 2013 (3-0), ending with their worst run against them (11 games).
- No other player has scored more goals against Atletico this season in all competitions than Inaki Williams (three, level with Cristiano Ronaldo).
- Atletico have failed to score in consecutive games in all competitions for the first time this season.
- Williams has scored four LaLiga goals against Atletico, more than against any other opponent.
- Kenan Kodro has scored the fastest goal by a substitute in LaLiga this season (27 seconds).
- Atletico failed to register a single shot in a first half of a LaLiga game for the first time under Diego Simeone.
Simeone's side have their third successive away game after the international break when they visit Deportivo Alaves on March 30, a day after Athletic visit Girona.