Leaders took another stride towards retaining their league title but were made to work by the division's rock-bottom team who took a shock lead before succumbing to their hosts
An unexpected opener from Corona was cancelled out by a Lionel Messi penalty before Thiago nodded in and the Argentinian added a third.
Almeria made a gutsy start to the game as they kept Barcelona at bay for the opening 15 minutes. However the home side soon quickened the tempo as Thiago fired over wastefully after some tricky dribbling by Bojan.
Messi then had two chances, the first poached from nothing as he thumped his shot wide but his second was a characteristically mesmeric run as he danced past three challenges. His outside of the boot finish went the wrong side of the post as the Camp Nou crowd expected the diminutive forward to put the Andalucians to the sword.
Although Almeria hung on during a sustained period of pressure, a clean sheet was obviously not the only objective today. Ortiz and Piatti combined efficiently but the latter could not latch onto the return ball to work Pinto in the Barcelona goal.
The opening half ended goalless but Diego Alves in the away side's goal kept it so as he amalgamated with the post to keep Messi out once more as the World Player of the Year threatened again with another captivating run.
Messmerising | The Argentina international takes on three defenders
A whirlwind beginning to the second half livened up a fruitless encounter as David Villa hit the post following the best move of the game for Barcelona.
However, Almeria shocked the home crowd by going up the other end immediately after and taking the lead. The Andalucians broke at pace and Piatti's perfectly weighted through ball found Corona unmarked who slotted the ball into the home side's net in the 50th minute.
Unfortunately for the visitors, goalkeeper Diego Alves made a rash decision a short time after they took the lead by clipping Villa in the box and a penalty was awarded. Messi sent the 'keeper the wrong way to level matters with a calm finish to the bottom right corner in the 53rd minute.
The brave rearguard of Almeria was broke once again when Thiago scored in the 64th minute. The Catalans took the lead when the 19-year-old glanced in a Messi corner past a despairing Alves.
The effort put in by the visitors was telling by now as the Blaugrana teased the opposition by playing keep ball. Chances were at a premium in the closing stages as Xavi, Inista and co. retained the ball efficiently to see out the win as Messi completed the rout.
Barcelona replied to Real Madrid's earlier message and keep the gap between the teams at eight points.