Real Madrid had claimed the overnight lead thanks to Saturday’s 2-0 home success against Granada before Barca and Atletico restored their one-point advantage with comfortable wins against outclassed opponents.
The joint leaders have 54 points from 21 matches, with Barca ahead on goal difference. Real are lurking ominously on 53 and Athletic Bilbao trail on 42 in fourth after they thrashed Osasuna 5-1 on Sunday.
The Barca fans paid tribute to veteran midfielder Xavi before kickoff at the Nou Camp after he reached the milestone of 700 official games for the Spanish champions this month.
The Spain playmaker turned in a typically impeccable performance controlling play in the centre and Malaga were forced to rely on the counter-attack to have any hope of troubling the hosts.
Barca’s Chile forward Alexis Sanchez clipped the post in the fifth minute and Lionel Messi sent a dinked effort narrowly wide in the 22nd before Gerard Pique fired in the opener five minutes before halftime.
The Spain centre back, who scored the equaliser in last weekend’s 1-1 draw at Levante, controlled the ball in the area from a Xavi corner and drilled it past Malaga goalkeeper Willy Caballero.
Pique headed against a post from another corner in the 54th minute and moments later Messi freed Pedro on the left of the area and the striker curled a shot into the corner.
Pedro turned provider just after the hour when he picked up another Messi pass and sent a low centre to the far post where Alexis tapped home.
An easy win, their 25th in a row at home in La Liga, was just the tonic Barca needed after a difficult week when president Sandro Rosell stepped down amid a probe into alleged irregularities in the signing of Brazil forward Neymar last year.
Rosell’s deputy Josep Bartomeu has taken charge and was watching from the VIP tribune.
Pique said the club’s institutional problems were unlikely to have much effect on the players.
“We will carry on competing as we have done these past years,” he told Spanish television broadcaster Canal Plus.
“Obviously a change in president is a subject of discussion among the general public but on the pitch we are professionals and we will try to win all the titles we can,” he added.
There was more positive news for Barca as their Netherlands midfielder Ibrahim Afellay came off the bench for the last five minutes of the game.
Afellay was declared fit this week after battling a series of injuries over the past two years and will give coach Gerardo Martino an extra option as Barca seek to defend their Liga title and chase Champions League and King’s Cup glory.
Spain’s record scorer David Villa, who joined Atletico from Barca in the close season, set his new club on their way in the eighth minute at Rayo’s Vallecas stadium in the Madrid suburbs when he struck a first-time shot high into the net from Diego Costa’s neat layoff.
Atletico goalkeeper Thibaut Courtois saved a 12th-minute Jonathan Viera penalty before Arda Turan, known in Spain as the Turkish magician, made it 2-0 on the half hour after more good work from Costa.
The Brazil-born forward fed Jose Sosa and despite having a clear shooting opportunity he unselfishly squared for Arda to finish into an empty net.
Rayo, who play some attractive football but have a leaky defence, pulled a goal back in the 40th minute when Viera finished off a sweeping move and Arda scored his second moments before the break.
The stocky and heavily-bearded midfielder nipped in at the back post and volleyed a deflected Gabi free kick in from a tight angle.
Costa, the second-highest scorer in La Liga this season behind Cristiano Ronaldo, appeared to have netted his 20th of the campaign in the 75th minute but it was ruled an own goal and attributed to Rayo midfielder Saul Niguez.
Joaquin Larrivey nodded a second for Rayo a minute later and Atletico had to withstand late pressure but Courtois capped another fine performance with a couple of impressive saves.
Barca, Atletico and Real are all in King’s Cup action this week when they will seek to capitalise on first-leg leads to secure a place in the semi-finals.
(Reporting by Iain Rogers, editing by Ed Osmond/Rex Gowar)