A third Lionel Messi hat-trick in four games helped Barcelona keep the pressure on La Liga leaders Real Madrid as they recorded a 5-1 victory over local rivals Espanyol on Sunday.

After falling behind to Sergio Garcia's early strike, Barcelona then took control of the Catalan derby.

Messi's 21st Liga treble, which took him to within two of Cristiano Ronaldo's record of 23 set on Saturday, a Gerard Pique header and neat finish from Pedro, was enough to see Barca take the spoils and leapfrog Atletico Madrid in second place with 34 points.

Real still lead the table with 36 points after a 3-0 win over Celta Vigo on Saturday.

Despite having not won at the Camp Nou since 2009 it was the visitors who started the brighter, creating the game's first chance after eight minutes, however Jordi Alba was able to clear Garcia's cross with Lucas Vazquez poised to tap in from close range.

Barcelona did not heed the early warning, and they soon found themselves behind.

Felipe Caicedo challenged Sergio Busquets just inside the Barcelona half, and as the Camp Nou waited for a whistle that never came from referee Ignacio Iglesias Villanueva, Sergio Garcia ran directly at a static Pique before firing past Claudio Bravo to stun the hosts.

It was Espanyol's first goal at the home of their illustrious neighbours since Ivan De La Pena's double saw them record a 2-1 win there five years ago.

Barcelona then reacted, with Xavi Hernandez, Neymar and Ivan Rakitic all seeing chances come and go as they began to dominate play.

After being brought down on the edge of the box, Messi saw the resulting free-kick bounce off the crossbar with goalkeeper Kiko Casilla beaten, and it only seemed a matter of time before the home side equalised.

Casilla then denied Pique and Alba as Barcelona pushed on, however they were almost made to pay five minutes before the break.

Espanyol broke at pace, however Victor Sanchez's heavy touch when latching onto Vazquez's through ball allowed Bravo to close down the space and keep his side in the game.

It was to prove a pivotal save as, on the stroke of half time, Messi equalised with the kind of goal that Barcelona have made their trademark.

Jordi Alba cut inside from the left, feeding Xavi Hernandez, who in turn laid the ball off to the Argentine who swept home from just outside the box.

With the momentum firmly behind them, Barcelona came out firing in the second period, and thought they had a penalty within 60 seconds of the restart when Eric Bailly brought down Neymar, however Iglesias Villanueva was unmoved.

The Brazilian, who was a menace throughout, then combined with Luis Suarez to find Messi on the edge of the box five minutes after the break, and the 27-year-old rifled a right-footed effort past a hapless Casilla to knock the wind out of their opponents' sails.

Two minutes later the advantage was doubled as a Rakitic corner was met by Pique, and from there on there was only one winner.

With 13 minutes remaining an Alba diagonal ball found substitute Pedro Rodriguez, who had earlier replaced Suarez, and the Spain international made no mistake to further stretch Barca's lead.

Nine minutes from time Messi capped off a fine afternoon as he scored his third, and his side's fifth, following a give and go with Pedro.