Casemiro hit the winner at San Mames as Real Madrid beat Athletic Bilbao 2-1 to extend their lead at the top of La Liga to five points.
A bright Bilbao side had put their opponents on the back foot early on, catching them by surprise numerous times, and almost fell behind after 10 minutes when Cristiano Ronaldo swept home Dani Carvajal's cross, though it was quickly pulled back for offside.
Fifteen minutes later though, they were behind when Ronaldo and Karim Benzema linked up, with the latter clinically slotting home his eighth league goal of the campaign from 10 yards out.
Though the goal momentarily knocked Bilbao for six, they improved in the second half and earned their just reward with 25 minutes to play, when Aritz Aduriz nodded past Keylor Navas after Raul Garcia had headed down Inaki Williams' far-post cross.
However, the lead lasted just three minutes, as an unmarked Casemiro brought down Ronaldo's flick and curled a low shot past Kepa to earn Zinedine Zidane's men three points and end Bilbao's seven-month unbeaten home run.
Athletic, who had not lost at San Mames since a 1-0 defeat to Barcelona on 28 August, started the game with a real spring in their step and had the best of the exchanges in the opening 10 minutes.
Inigo Lekue was a thorn in Carvajal's side on the right, pulling back a cross from the byline for Inaki Williams inside the first minute, before seeing his shot blocked by the Madrid right-back soon after.
But Zidane's men were never going to let their opponents get away with such early dominance and they had the ball in the net after 10 minutes but Ronaldo's effort was disallowed for offside.
Bilbao had a couple more chances to open the scoring themselves, but after two Oscar De Marcos crosses went begging and Yeray Alvarez missed, Real Madrid took the lead.
Ronaldo picked up a ball out of defence, beat the offside trap and made his way down the left, crossing for Benzema at the back post, who coolly slotted home from close range.
Athletic ended the first half as they had started it and carried that momentum forward into the second period, going close in the 48th minute when Sergio Ramos and Navas failed to communicate as Aduriz met Williams' cross.
On the hour mark, Williams lashed a shot towards Navas' near post, but the keeper produced a smart stop to keep it out but five minutes later Bilbao equalised
Williams' deep cross to the far post was met by Raul Garcia, who headed into the path of Aduriz and he nodded over the line to send the 49,000 inside San Mames into raptures.
But it was a lead that would last just three minutes before Casemiro put his stamp on the game.
Kroos hit a corner towards the near post, Ronaldo's slight touch flicked the ball on and into the path of an unmarked Casemiro, who had all the time in the world to feign a shot, see Kepa drop to his knees and finish.
The second goal took the sting out of Bilbao's tail and, though Williams shifted to a more central role to try and force a second equaliser, it didn't arrive.