Brazilian Neymar struck after 16 minutes put Barcelona on their way to victory and then Messi scored from a tight angle nine minutes later to double the visitors’ lead.
The only negative for Luis Enrique’s side was Jordi Alba getting sent off in the second half for earning two successive bookings, but the league leaders continued playing as if it was they who had an extra man, and could have extended their lead.
Espanyol defender Hector Moreno was then also sent off in injury time to complete a miserable afternoon for the hosts.
Atletico Madrid comfortably beat Elche 3-0 at home to resume normal service after being eliminated from the Champions League by Real Madrid in midweek.
The visitors came through the first half unscathed but fell behind to Antoine Griezmann’s header on 55 minutes, and Raul Garcia doubled the lead before the Frenchman pounced again, scoring a double for a third consecutive Primera Division game.
The win sees Atletico tighten their grip on third spot, while Elche remain in 14th place, six points above the relegation zone.
Victor Casadesus scored the only goal as strugglers Levante claimed a valuable 1-0 win at Getafe??at Coliseum Alfonso Perez.
Casadesus broke the deadlock in the 35th minute and Lucas Alcaraz’s side held on to claim three valuable points in their quest to avoid relegation.
Levante started the day just one point clear of the bottom three, but the win over 13th-placed Getafe boosted them above Eibar and into 15th place.
The evening’s late game saw David Moyes’ Real Sociedad grind out a 0-0 draw against sixth-placed side Villarreal.