La Liga - Barca ease to win against Zaragoza
Barca did not have to be at their best but easily beat weak opposition as Pique headed them into an 18th-minute lead, Messi doubling the advantage just before the break.
Zaragoza offered little save a brief spell of pressure early in the second half, but any hopes of a fightback were swiftly put to bed when Puyol forced home a scrappy third on 54 minutes.
Villa, who had previously only scored three goals this season, came off the bench to add a fourth and was mobbed by his team-mates, who were delighted that he had found his scoring touch.
Barca started a touch slower than usual, perhaps regaining their rhythm after the long international break, or maybe adjusting to their striker-free formation, with David Villa benched.
They still exercised total control though, dominating possession and restricting their visitors to the occasional fruitless counter-attack: the most Victor Valdes had to do was pluck the odd cross or high ball out of the sky.
The hosts almost drew first blood on nine minutes when a low Cesc Fabregas ball was missed by the sliding Messi: Alexis Sanchez picked up the loose ball but elected to cross when the goal was gaping, although admittedly from an acute angle. Messi again hurled himself in but Roberto was able to claim.
Puyol then headed wide from a corner when it seemed easier to score, arriving unmarked but scuffing the ball with the side of his upper body when any contact from the forehead would surely have resulted in the opener.
Zaragoza, who had the second-worst defence in the division before the weekend kick-off, failed to learn from that escape, allowing Pique to ghost in unmarked two minutes later as he powered Xavi’s corner past the stranded Roberto.
That sparked Barcelona into something approaching their standard level of play as they got their passing game locked in.
They should have scored a hatful as Roberto found himself - and some of his defenders - pulling out all the stops to deny Messi in particular, the Argentine wreaking havoc with his dribbling and near unplayable runs.
On 29 minutes, the World Player of the Year flicked one effort against Roberto when clean through, before picking up the loose ball out wide and driving it into the side netting.
Immediately afterwards Messi wriggled clear only to be denied by the Zaragoza shot-stopper again, with Fabregas picking up the loose ball but denied by Maurizio Lanzaro’s block: Sanchez got hold of it but his shot was batted away by Roberto.
Two minutes following that exchange, Messi went on a trademark dribble but found Lanzaro in his way, with Roberto again called into action as Fabregas had a pop.
But the second goal was inevitable and again it came down to some hapless defensive organisation, with Lanzaro and on-loan Celtic defender Efrain Juarez contriving to play Messi onside as he raced on to Isaac Cuenca’s pass, skipped away from Fernando Meira and slid a low finish across Roberto and inside the far post.
That was two minutes before the break and 60 seconds later it should have been 3-0 as Fabregas and Maxwell combined on the left before the Brazilian left-back drilled a low cross that the former Arsenal midfielder failed to meet from five yards.
Possibly buoyed by a relatively rare starring show for Argentina in their World Cup qualifying win over Colombia, Messi was enjoying himself, denied a second after one of his typical runs, Juarez blocking the finish.
Barca sprung out of the blocks for the second half with serious intent, Fabregas denied a superb goal by Roberto’s excellent low save after a one-two with Messi cut the visiting defence in two.
Angel Lafita, on as a half-time sub, went on a great individual run before firing over as Zaragoza showed some spirit against the odds.
The spirit was in vain though as, a couple of minutes after that effort, Puyol bundled the ball over the line after his initial effort was kept out by Roberto, Seydou Keita setting up the chance by knocking down Fabregas’s lofted ball.
Barca were approaching peak form now as Messi had another effort blocked by Juarez, while Andres Iniesta - rested but brought on for a late run-out - poked just wide after Messi’s wonderful run and pass.
The fourth came soon afterwards though as Cuenca capitalised on a loose pass by David Mateos, rounding the on-loan Real Madrid defender before flashing over a wicked cross that Villa dived in to head past the helpless Roberto.
Roberto - who had a fine game despite conceding four - was again alert to deny Iniesta after his one-two with Villa unlocked the defence, while Cuenca blasted over after a mazy run from Messi as Barca pushed for a fifth.
But that was it as far as goals were concerned, the win putting Barca top briefly on goal difference ahead of joint-leaders' Real Madrid’s tough game at Valencia.