Lionel Messi scored a hat-trick and Ousmane Dembélé came off the bench to set up a late goal for Luis Suárez as Barcelona romped to a 5-0 win in the Catalan derby against Espanyol at the Camp Nou.

With their title rivals from Madrid, Real and Atlético, having dropped points with draws earlier in the day, Barcelona were looking to strike an early blow at the top of the table.

Messi set Barcelona on their way with the opening goal after 26 minutes, although he looked to have been offside. The Argentinian then doubled the lead 10 minutes before half-time, and completed his hat-trick just after the hour.

Gerard Piqué’s header made it 4-0 with three minutes left before the £96.8m signing Dembélé, on as a late substitute, laid a fifth on a plate for Suárez in stoppage time to round off a rapid team move starting from Marc-André ter Stegen in goal.

The comprehensive win puts Barcelona, who host Juventus in the Champions League on Tuesday night, two points clear at the top of the table, having yet to concede a goal in their three La Liga victories.

It was a 42nd career hat-trick for Messi, 38 of which have come for Barcelona, and the Barcelona coach Ernesto Valverde hailed him after the match.

“I am happy for Leo who scored three goals and is extraordinary,” he said. “We pulled through a complicated game, because these kinds of matches are always tough. Despite the result, it wasn’t easy. Espanyol fought very well, but we have great players like Messi, who scored three goals, and Suárez, who gave everything like the rest of the team.”

Despite Barcelona’s positive start, Valverde wants to keep things in perspective as they look to maintain an advantage over champions Real Madrid. “We are at the beginning of the season and the distances are not significant, but it is better to be ahead than behind,” he said. “It does not mean anything, but being ahead is always good.”

Valverde had resisted the temptation to throw Dembélé straight into the thick of the action following the 20-year-old’s big-money switch from Borussia Dortmund, but the loudest cheer of the night from the Camp Nou faithful greeted his introduction on 68 minutes, when the result was already secure.

“The idea is to give Dembélé minutes, we have a lot of hopes for him and this game was a first step,” the Barcelona coach said. “His team-mates know that he has real quality.”

The Espanyol coach Quique Sánchez Flores, meanwhile, felt his team deserved more from the match, having seen Pablo Piatti hit the post just before half-time. “The result is excessively wide,” he said, on the Espanyol website. “We have to learn and be careful with the details, but there is nothing from this match which does not make us stronger.”