'He is a genuis when it comes to free kicks, ' the commentator yelled when Messi netted his first goal from 30-ish yards away from the goal post.
Ousmane Dembele and Luis Suarez also scored in the Catalan derby for Barcelona, which opened a three-point lead over Sevilla and Atletico Madrid. A goal in each half with an assist in between saw the 5th best player in the world, according to France Football, break another La Liga record.
Espanyol's fourth consecutive league defeat left them ninth in the standings, but they didn't stand a chance with Messi in this mood.
Dembele turned provider this time, slipping his fellow forward in in the left-hand channel, with Suarez doing brilliantly to hold off the challenge of a defender and somehow squeeze a finish through the legs of Lopez and into the far corner from the narrowest of angles.
Following Sevilla's 1-1 draw at Valencia, where the hosts hit a dramatic equaliser in stoppage time, Barcelona made no mistake at the RCDE Stadium, where they were 3-0 up at half-time.
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A group of hooded youths earlier broke away from the march and hurled stones at police who used tear gas to disperse them. The policeman, Epaminondas Korkoneas, said he had not aimed for the teen, but that he was killed by a ricochet.
Barcelona have made one change for their clash with Espanyol on Saturday evening.
That change is up front where Luis Suárez comes in for Philippe Coutinho.
Barcelona were caught out at the back in the 74th minute when Duarte stabbed the ball in at close range from a free-kick.
'We knew about the danger of Espanyol, especially at home. Messi's shot was struck just as perfectly at the first one, curling over the wall and into the top corner.
In a rare moment of action in the Barcelona penalty area, Victor Sanchez's header dropped wide of the far post.