Barcelona took full advantage of Real Madrid's heavy defeat in the capital-city derby to close the gap at the top of the Primera Division to a single point on Sunday night.
Lionel Messi had a hand in all of Barcelona's goals, scoring one, as they trounced Athletic Bilbao 5-2, with strikes from Luis Suarez, Neymar, Pedro and an Oscar de Marcos own goal taking the Catalan giants clear.
Mikel Rico and Aritz Aduriz notched for Bilbao, but they never looked capable of springing an upset against Luis Enrique's side.
The win takes Barcelona up to 53 points and right onto Los Blancos' coattails after they lost 4-0 to third-placed rivals Atletico Madrid on Saturday.
It extends Barca's winning streak to nine games in all competitions, with the Catalan giants turning the screw ever since their shock 1-0 defeat to David Moyes' Real Sociedad last month.
Luis Enrique's side never looked like slipping up at San Mames and made a confident start before Messi, with the help of a deflection, broke the deadlock in the 15th minute.
The Argentinian lined up a free kick from 25 yards with his familiar swagger, but it was a slight nick off the wall that ultimately made the difference, sending the curled shot just past the despairing dive of Bilbao keeper Gorka Iraizoz.
Aduriz was lively for the hosts and came close to levelling when his right foot met Iker Muniain's cross to the far post at full stretch, but Barca keeper Claudio Bravo showed great reflexes to tip his toepoke wide.
It looked like being another frustrating day in a Barcelona shirt for Suarez when his header from two yards out was remarkably punched clear by Iraizoz, but in the 25th minute the former Liverpool striker was finally given something to smile about.
After his free-scoring form for Liverpool last season many expected the 28-year-old to light up La Liga, but he has found goals harder to come by since his 75 million-pound move to Spain.
Before this game he had only plundered two league strikes for Barca, but he looked back to his best after combining well with Messi on the right before sweeping home a first-time shot from the edge of the box that gave Iraizoz no chance.
While the former Liverpool man's frustrations were relieved, Aduriz's began to grow as his close-range header on the half-hour mark this time beat Bravo but found a post.
With Barca taking a 2-0 advantage into the break it seemed like the game was all-but settled, but the second half exploded into life with a four-goal flurry around the hour mark.
Bilbao made things interesting with Rico tucking home after Aduriz's shot was parried by Bravo in the 59th minute, but that was short-lived as De Marcos diverted Messi's effort into his own net soon after.
Neymar made it 4-1 in the 64th minute with a venomous low drive from just inside the box, after being released by Messi, before Aduriz finally got on the scoresheet by firing through Bravo's legs from an acute angle to effectively take things back to where they started - with Barca having a two-goal cushion at 4-2.
Hopes of a Bilbao fight back were dented in the 75th minute when referee Antonio Miguel Mateu Lahoz gave Xabier Etxeita a straight red for nasty high tackle, with studs up, on Suarez.
The Uruguayan went down clutching his knee, before hobbling off. He tried to carry on before being withdrawn after 80 minutes.
There was still time for Barcelona to add gloss to the scoreline with a typically well-worked team goal as Pedro tapped home after Messi and Sergio Busquets scythed the hosts' backline open.