At the Nou Camp, home of the dethroned champion, Messi's (pictured) treble made him the first man to score 68 goals in a season for a European top-flight club, breaking the record of 67 set by former Bayern striker Gerd Mueller in 1972-73.

After the home fans paid warm tribute to coach Pep Guardiola, who announced on Friday he was stepping down at the end of the season, captain Carles Puyol volleyed Barca ahead in the 13th minute.

Salomon Rondon leveled with a header in the 26th before Andres Iniesta was felled on the edge of the area and Messi stroked in the spotkick.