After Real and city rivals Atletico Madrid had played out a 2-2 draw earlier in the day, Sunday's late contest afforded Barcelona the chance to get right back in the title mix after their costly defeat at Real Sociedad last weekend.
Alexis Sanchez set the hosts on their way in the 10th minute before a superb Lionel Messi free-kick made it 2-0 inside 25 minutes.
A moment's sloppiness in the Barca backline allowed Angel Trujillo to pull one back for Almeria and at 2-1 Barca endured more than one or two nervy moments as the visitors probed for a leveller.
It took until the 83rd minute for Barcelona to finally put the contest to bed, Carles Puyol following up with a smart finish after Messi's header had come back off the bar, while there was still time for Xavi to inflate the scoreline further with a sumptuous fourth.
The hosts looked threatening from kick-off, with Dani Alves in particular proving a nuisance with a couple of dangerous forays into the Almeria box.
Gerardo Martino's men soon turned their early threat into the opener when Neymar picked out Cesc Fabregas in the area, the former Arsenal man shifting the ball inside and firing in a low drive that Esteban could only parry, allowing Sanchez a simple finish.
Barca maintain their stranglehold on the match without seriously threatening the Almeria goal a second time, but that changed in the 24th minute when Corona brought down Messi 25 yards from goal.
The Argentina international unsurprisingly picked himself up to take the set-piece and did not disappoint an expectant Nou Camp with what came next, the prolific forward firing home a wonderful effort that began off-target before curling wickedly into the top-left corner of Esteban's goal.
The hosts were good value for their lead and looked set to dominate from that point, but just three minutes later some slack defending and poor goalkeeping from Victor Valdes gifted Almeria a lifeline.
Corona's corner should have been dealt with by the Barca backline but when Valdes dithered his defenders did likewise and Trujillo capitalised with a headed finish.
Barca remained the dominant force in the contest en route to racking up 27 attempts on goal, yet they looked vulnerable on the occasions Almeria did mount an attack, with last weekend's 3-1 loss at Sociedad no doubt playing on their minds.
It was therefore crucial for the hosts to add a third, and they duly did so seven minutes from the end when Messi climbed to meet a corner with a firm header than came down off the crossbar, where the waiting Puyol was on hand to turn the ball in.
And in the final minute the Catalans had their fourth, another member of the Barca old guard in Xavi curling home wonderfully from 20 yards.