Lionel Messi scored twice to earn Barcelona a 2-0 derby win over Espanyol and send them 13 points clear at the top of La Liga on Saturday.
With second-placed Atletico Madrid travelling to Alaves later in the day, the champions took advantage of the chance to extend their lead.
A dull match was decided by Barcelona's number 10, who lofted home a free kick after 71 minutes and slotted in from substitute Malcom's cross towards the end.
Messi, the division's top scorer with 31 goals, suffered criticism in his native Argentina after withdrawing from a friendly against Morocco because of a groin problem, but was hailed by Barcelona fans after taking them one step closer to retaining the title.
Ernesto Valverde started Messi along with Luis Suarez, who had recovered from an ankle sprain.
But the duo and Philippe Coutinho were kept quiet in a tight first half, with Espanyol's five-man defence not giving the South American trio any space.
With Malcom's introduction in the final half hour, the game began to open up.
The Brazilian winger had a cross shot tipped wide by Diego Lopez, with Coutinho firing over the bar as Barcelona pushed for a winner.
The Catalans were short on inspiration until Messi produced a cheeky dinked free kick, which midfielder Victor Sanchez could not keep out on the goal-line, before tucking home his second on the break.
Barcelona were far below their fluid best but two moments of skill from talisman Messi secured three points from an otherwise forgettable game.
Wasteful Bayern stumble in title race, Dortmund win
Champions Bayern Munich stumbled to a 1-1 draw at Freiburg on Saturday to hand the Bundesliga top spot back to Borussia Dortmund, who beat VfL Wolfsburg 2-0.
The Bavarians, who had won 13 of their previous 14 league games, cancelled out Lucas Hoeler's third minute goal with Robert Lewandowski's 199th Bundesliga goal in the 22nd.
But the Poland striker's sensational volley was not enough and he wasted a bagful of golden scoring chances in the second half, including a point blank header, and even hit the woodwork in stoppage time.
Bayern are on 61 points, two behind Dortmund whom they will meet next week.
RB Leipzig, who are third on 49, host Hertha Berlin later on Saturday.