Lionel Messi scored two exquisite free kicks as he netted his first hat-trick of the season in a 4-1 win over Celta Vigo on Saturday which took Barcelona back to the top of La Liga after a difficult week.Barca's captain coolly converted a penalty to put the champions ahead in the 23rd minute but gave away a foul in a dangerous area which led to Lucas Olaza levelling for Celta with an outstanding strike from a free kick in the 42nd.But Messi restored Barca's lead right before halftime with a stunning free kick of his own, curling the ball into the top corner.He conjured up an almost identical strike at the start of the second half to complete his treble and match Cristiano Ronaldo's record of 34 hat-tricks in Spain's top flight.Sergio Busquets struck a fourth goal in the 85th to round off a first win for Barca in three games, after falling to a shock 3-1 defeat at Levante last week in La Liga and drawing 0-0 at home to Slavia Prague in the Champions League.Barca lead the standings on 25 points after 12 games, level with second-placed Real Madrid who eased to a 4-0 win at Eibar.