Lionel Messi fittingly scored the goal which ensured Barcelona retained their La Liga title with a 1-0 win over struggling Levante.
The Argentina international, rested for the first half as coach Ernesto Valverde had one eye on next week's Champions League semi-final, first leg against Liverpool, scored his 34th league goal of the season.
With three matches remaining, a nine-point lead over Atletico Madrid and a superior head-to-head, an eighth title in 11 years was secured, although amazingly it was the first time since 2010 they had clinched it at the Nou Camp.
They remain on track for a third treble since 2009 with the Copa del Rey final against Valencia next month and their clash with Liverpool, starting with the first leg at the Nou Camp on Wednesday.
How Barca sealed their title win
It was far from straightforward for Barca 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.
Super-Sub
Rested for the first half, Messi scored his 34th league goal of the season from the substitutes' bench.
Messi has won more points with his goals than any other player in La Liga this season (17 points with 34 goals).
What's next for Barca?
Barcelona's attention now turns to winning a first Champions League title since 2015. Standing in their way is a semi-final clash against Jurgen Klopp's Liverpool.
The first leg takes place at the Nou Camp on Wednesday (May 1) at 8pm with the return leg at Anfield the following Tuesday (May 7), also at 8pm.
What about the treble?
Barcelona can make it a double by adding Copa del Rey success to their La Liga triumph when they take on Valencia in the final at the Estadio Benito Villamarin in Seville on Saturday May 25.
If they come through their Champions League semi-final against Liverpool they would face either Tottenham or Ajax in the final Wanda Metropolitano, Madrid on Saturday June 1 for the chance to complete a third treble since 2009.
Elsewhere in La Liga
Atletico Madrid scraped a 1-0 home win against Real Valladolid to at least require Barca to win to clinch the title.
Had Atletico lost, Barca would have been crowned champions before they kicked off, but Joaquin Fernandez's second-half own goal secured Diego Simeone's side a fourth straight league win.
The visitors were unfortunate to leave the Wanda Metroplitano Stadium empty-handed as home goalkeeper Jan Oblak made several fine saves before Fernando Calero's stoppage-time header hit a post.
Atletico moved nine points clear of third-placed Real Madrid, who play at Rayo Vallecano on Sunday.
Athletic Bilbao missed the chance to climb into a Europa League place as they were held 1-1 at home by Alaves.
Benat Etxebarria's free-kick for Athletic was cancelled out by Alaves striker Borja Baston in first-half stoppage time.
Mid-table Leganes were held 0-0 at home by Celta Vigo, who edged three points clear of the bottom three who all play on Sunday.