Having secured a morale-boosting victory over Real Sociedad on Monday, Xavi’s side came flying out the blocks as Robert Lewandowski saw an early effort thwarted by Luis Maximiano in the Almeria goal.
Barca’s bright start was duly rewarded with a breakthrough in the 14th minute when Hector Fort’s cross was headed into the roof of the net by Lopez for his ninth goal of the season.
The hosts - still searching for their first league victory on home soil this season - threatened an immediate response, but Marc-Andre ter Stegen stood firm in the Barca goal to deny Choco Lozano from close range.
Chances continued to flow as the first half progressed, with Lamine Yamal crashing a strike against the post for the visitors, while at the other end, Adrian Embarba came within inches of a leveller when his well-worked effort also cannoned off the woodwork.
Almeria carried the momentum of that missed opportunity into the early stages of the second half, but further profligacy in the final third from Lozano and Lucas Robertone continued to frustrate the home faithful.
Grateful to still be ahead, Barca punished the hosts with an all-important second goal in the 67th minute, as Lopez latched onto Sergi Roberto’s cut-back to sweep a clinical finish beyond Maximiano.
That all but ended the hosts’ hopes of a late turnaround as Xavi’s men coasted through the final stages to secure a crucial win, extending their dominant record in head-to-head meetings to just one defeat in the last 18.
As for Almeria, they’ll be desperate to pick up something from their final two games with no side in the Spanish top flight having finished with as few as their 17 points this century.
Flashscore Man of the Match: Fermin Lopez (Barcelona)