Messi first found the top corner from the edge of the penalty area to put the visitors ahead.

Ousmane Dembele doubled Barca's lead with a curling finish before Luis Suarez made it 3-0 from a tight angle.

Another sensational Messi set-piece - this time from further out - completed the victory.

Sevilla had missed the chance to leapfrog Ernesto Valverde's side earlier on Saturday as they were held to a 1-1 draw by Valencia.

That allowed Atletico Madrid, who recorded a comfortable 3-0 victory over fourth-placed Alaves, to briefly move level on points with the top two.

Barca, who face Tottenham in the Champions League on Tuesday, also hit the woodwork twice in a one-sided first half, Suarez slicing against the post from Messi's pass before the latter crashed a header against the other post.

Espanyol improved after the interval and had a goal disallowed for offside when Oscar Duarte stabbed home Sergio Garcia's cross from close range, but a comeback was never a serious possibility for the hosts.

The win cements Barcelona's place at the La Liga summit, while Espanyol drop to ninth after slipping to a fourth consecutive league defeat.