Lionel Messi, Gerard Pique and Andres Iniesta were among those excused duty against the league's bottom side, but the reserves enjoyed near total dominance in the first period, the only surprise being that Alexis Sanchez's 38th-minute goal was all they had to show for it.
Messi and Iniesta were sent on to close out the victory in the second half and combined for the second goal, a superb Messi finish for his 40th league goal of the season at the Nou Camp.
The first half was just as one sided as it was expected to be, but Barca missed a glut of chances before the opener arrived.
Dani Alves had the first good sight of goal in the 12th minute, drilling hard but straight at Daniel Aranzubia from a tight angle.
Two minutes later Cesc Fabregas sprung the offside trap and took down Alves' chipped through-ball, only to blaze over.
Thiago Alcantara's defence splitting pass then gave Cristian Tello a fine opportunity, but Aranzubia smothered the forward after he took a touch.
Alexandre Gama hassled Alexis enough to prevent him tapping in Tello's square ball after 21 minutes and Aranzubia followed up with a wonderful save.
Villa was the man denied after he attempted to psych out the keeper in a one-on-one, only to see him stand tall and beat away a belated shot.
Fabregas blasted the loose ball over.
The breakthrough goal finally came in the 38th minute, Alves crossing to an unmarked Alexis eight yards from goal.
His header was almost saved again by Aranzubia, but any debate about whether it had crossed the line was rendered moot when the Chilean followed up and launched the ball into the roof of the net.
The lead might have been two at the break had Villa not shot wastefully from a good position.
Barca were unusually flat for the 20 minutes after the restart, their play lacking all the momentum it had shown before the interval.
Mindful, perhaps, of letting the relegation strugglers back in, the home side sent for Messi and Iniesta within the space of four minutes.
The pair almost fashioned a second goal in the 74th minute when Iniesta fired in a slow, skiddy shot which was spilled by the goalkeeper and thrashed home by the Balon d'Or winner.
His celebrations were cut short by an offside flag, though.
Messi then fluffed a shot from eight yards out, but made amends two minutes before the close.
Iniesta set the move in motion with a quick shift of gears in midfield, Messi exchanged a one-two with Alves and then nonchalantly flicked over Aranzubia to continue a scoring streak that contains his last 17 La Liga matches.