They remain on track for a third treble since 2009 with the Copa del Rey final against Valencia next month.

However, it was far from straightforward against opponents who belied their position just three points clear of the relegation zone with a bold display which could, and probably should, have earned them a point.

Philippe Coutinho looked to be giving that little bit extra with a visit from his former club on the horizon and he could have had a first-half hat-trick as Barca's best chances fell to him.

The best by far was a 25th-minute free header eight yards out which he directed straight at Aitor Fernandez, having seconds earlier failed to properly test the goalkeeper when finding space on the left of the penalty area.

Coutinho also hit the crossbar with a free-kick having taken responsibility off another ex-Red Luis Suarez, who was first to test Fernandez with a shot on the run he took early to catch out his opponent only to see his effort turned behind.

Messi replaced Coutinho for the start of the second half and was soon into his stride, although a run and low shot was comfortable for Fernandez, while Ivan Rakitic bent a shot just wide.

There was, however, only one man who was going to score the goal which retained the title and in the 62nd minute Messi struck, controlling Arturo Vidal's header with one touch back onto his left foot before placing a shot beyond Fernandez and inside the far post.

But Levante's confident performance up to that point had proved they had not come to the Nou Camp to wave through Barca's title coronation and substitute Jose Luis Morales should have scored when he out-paced the defence but he blazed over.

Despite the lead Barcelona were far from convincing, offering hope to Liverpool they can nick a crucial away goal or two next week, and in the last minute another substitute Enis Bardhi hit the post to almost spoil the party.

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