Video: As Barcelona slip, Atletico or Real Madrid could also win the Spanlish La Liga now
Messi's team, which looked like runaway winners earlier, has lost its last two league games and now have a very slim lead with six games to go.
At the start of March, Barcelona looked like they would stroll to the title. They had scored nine goals in two matches and conceded just once. They looked invincible.
Now, after two consecutive defeats, a title race which had looked done and dusted has suddenly been blown wide open.
Barcelona slipped up against Real Sociedad on Saturday, losing 1-0 and extending a jinx which goes back till 2007. But what it also means is that after going unbeaten in all competitions for six months, Barcelona have now not won in their last three league games and their lead at the top is just three points.
Atletico Madrid at 73 points and Real Madrid at 72 are now snapping at Barcelona's heels.
The loss against Sociedad occurred after a dispiriting display at home in the El Clasico against Real Madrid where they went down 2-1, courtesy a great finish from Cristiano Ronaldo.
With just six games to go, Atletico and Real Madrid have been given an opening. Can they capitalise?