Barca had to play the majority of the second half with 10 men following Jordi Alba's red card, but Espanyol, who had Hector Moreno sent off in stoppage time, could not respond as they lost for the first time in seven league games.
Here, Sports Mole dissects the 90 minutes of action in Barcelona.
On target: 2
On target: 5
Was the result fair?
There is no question that Espanyol put up more of a fight in the second period, but Barcelona - on their first half-performance alone - certainly deserved to claim all of the points in the Catalan derby. The visitors led by two goals at the interval, but it really could have been five or six, with Messi, Neymar and Luis Suarez absolutely running riot, with all three showing signs of their best form. Barca had three excellent chances before they eventually took the lead after 17 minutes, before it became 2-0 just eight minutes later.
It did appear that the home side would be on the end of a hiding at that stage, but in fairness to Sergio Gonzalez's team, they were much improved in the second period. Christian Stuani had a couple of excellent chances, while Lucas Vasquez also passed up a good opportunity as the pressure developed. The fact that Barca had Alba sent off for two yellows in quick succession certainly helped, but Espanyol just could not make the breakthrough. Both sides were to finish with 10 men in Barcelona, meanwhile, with Moreno also seeing red late on in similar circumstances to Alba - two quick yellow cards for dissent.
Espanyol entered the match having not beaten their near-neighbours in their last 11 attempts, but there was a general feeling around the stadium that this could be the end of that poor run. They really needed a fast start, but it was the total opposite as Barcelona took immediate control of the game. The two centre-backs - Moreno and Alvaro Gonzalez - were pulled all over the park in the early moments. Barca could and probably should have been two ahead inside six minutes, but Neymar and Suarez both found Kiko Casilla in good form. It did eventually become 2-0 in the first period, but no real blame can be attached to the home side's back four, with Barcelona's movement in the final third just too difficult to contain.
As mentioned, there was a real improvement in the second period, which unsurprisingly, coincided with Barca's red card. There were no real opportunities for the hosts in the opening 25 minutes of the second period, but Stuani and Vasquez both came close late on, while it was Espanyol that continued to look the more likely in the latter stages. Had a goal arrived with time to spare, a second might well have followed, but they just could not find the back of the net. Insult was then added to injury when Moreno - who will now face a suspension - was sent off after collecting two yellow cards in quick succession.
Barcelona boss Luis Enrique made just two changes to his XI following their European exploits during the week, with Claudio Bravo and Rafinha both returning to the team. Enrique might have expected a difficult start such was the atmosphere inside the stadium, but his team were in control from the first whistle. In fact, it is difficult to remember an opening 30 minutes of a game at this level that Barcelona have dominated to such an extent. Andres Iniesta was pulling the strings in midfield, while Neymar, Messi and Suarez were all threatening in the final third and it could have been five or six at the break.
The first goal was sensational as Suarez stepped over a low Alba cross, allowing Neymar to fire into the bottom corner. The party tricks were in full flow and the second was also excellent as Suarez picked out Messi at the far post and the Argentine slid his effort into the bottom corner. Neymar and Messi both came close to adding to the tally early in the second period, but the former was denied by Casilla, before Messi struck the post from a tight angle. Opportunities were few and far between as the half developed, with Espanyol more of a threat. However, the away side stayed strong at the back to record a clean sheet and pick up another three points. As it stands, they are five points clear of second-place Real Madrid, who face a difficult trip to Celta Vigo on Sunday evening. Any slip up from Los Blancos would probably end the race.
Sports Mole's man of the match
Neymar: In truth, any one of Barcelona's front three could have been recognised here. Neymar just wins it, however, following an excellent display. The Brazilian opened the scoring after 17 minutes with a fine finish and he gave the Espanyol defence nightmares throughout the match with his constant movement and ability in possession. Question marks over his ability to influence games have disappeared this season.
It is never nice to see red cards issued, especially when the reasons are not particularly serious. Referee Antonio Mateu sent off two players in Barcelona and both were in similar circumstances. Barcelona's Alba was given his marching orders for dissent early in the second period, before Espanyol centre-back Moreno saw red late on for exchanging words with the Spanish official. What was said will more than likely remain private, but it seemed a shame to lose both players for incidents that were extremely minor.
It was not a particularly busy first period for referee Mateu, with just one yellow card issued. However, it proved to be an event-filled second 45 minutes as he sent two players off and issued five more cards. As mentioned, the official might have been overly-picky when it came to the red cards, while he was also quick to whistle, especially in the second period.
Espanyol: Sergio's side return to action away to Granada on Thursday.
Barcelona: Next up for Barca is a home match against Getafe on Tuesday.