Ivan Rakitic was brought in at the 68th minute to replace Sergio Busquet wasted no much time before firing in a Lionel Messi pass on the 71st minute giving Barcelona the lead after a goalless first half against Athletic Bilbao.
The substitute latched onto Lionel Messi’s pass before slotting home with 19 minutes to go.
It was a 15th La Liga assist of the season for Messi, who remains on 699 career goals despite going close himself on two separate occasions in the closing stages.
Real Madrid can go back to the top if they beat Mallorca on Wednesday.
Barcelona were far from their best but did enough to grind out this victory. With Real Madrid having a better head-to-head record, Barca need their rivals to slip up even if they win every remaining game.
Mid-table Athletic had beaten the Catalans twice this season – on the opening day of La Liga and in the Copa del Rey quarter-final – but failed to test goalkeeper Marc-Andre ter Stegen once.