Barcelona regained the lead after 28 minutes, however, when Alex Song struck from inside the box and Messi added his second to wrap up the points in the second period.
Here, Sports Mole dissects the 90 minutes of action between the two La Liga rivals.
On target 3
On target 2
Was the result fair?
On the balance of play, you would have to say yes. But make no mistake about it, this was not a vintage performance from Barcelona. It is becoming a regular occurrence this season. They are winning matches without really getting out of second gear. Zaragoza were not embarrassed, but they never looked capable of taking something from the match.
6/10. It is always difficult to criticise a team that has won the match. Whether or not they would have raised their game if needed is open to interpretation, but it was a slightly lazy performance from the Catalan outfit. That said, they burst into life when they were pegged back with an equaliser and controlled the 90 minutes.
Real Zaragoza's performance
6/10. Zaragoza were by no means embarrassed this evening and it is difficult to see what they could have done differently. Maybe their willingness to attack left gaps in their defence, especially after they equalised, but they struggled against a Barcelona defence that had Gerard Pique and Carlos Puyol back in tandem.
Sports Mole's man of the match
Lionel Messi: How can we give it to anyone else? The little Argentine continues to break records and he added another two goals this evening. But a special mention must be given to Puyol who was superb on his return.
Biggest gaffe of the match
It is easier said than done, but Zaragoza simply had to quell the Barcelona threat after scoring their equaliser. Instead they attempted to attack and were soon pegged back.
Miguel Ayza had a fairly straightforward 90 minutes of action this evening. The Spaniard went unnoticed for large periods of the match, which is always a good sign for a referee.
Barcelona: The Catalan outfit return to Champions League action away to Spartak Moscow on Tuesday before travelling to Levante in La Liga next weekend.
Real Zaragoza: Zaragoza will attempt to return to winning ways when they host Celta Vigo in La Liga on November 26.