Lionel Messi racked up 50 goals for the sixth year in a row while fellow forwards Luis Suarez and Antoine Griezmann were also on target as Barcelona turned on the style to beat Alaves 4-1 on Saturday and ensure they will end 2019 top of La Liga.
With Barca's nerves setting in at the Camp Nou after the visitors had fought back, Messi produced a jaw-dropping strike to restore Barca's two-goal lead, holding off three defenders outside the area before smashing into the net.
It was a fitting way for the Argentine to reach a half-century of goals for club and country in 2019 — the sixth straight time he has achieved the feat in a single calendar year and the ninth time in all in his career.
Griezmann had put Barca ahead in the 14th minute with a wonderful first-time strike into the bottom corner from a Suarez cut-back and Arturo Vidal also knocked home a pass from the Uruguayan to round off a dominant first-half display.
Alaves midfielder Pere Pons pulled a goal back in the 56th minute with a diving header which briefly caused panic in the home side who were fortunate not to concede an equaliser.
But Messi settled Barca down by restoring their two-goal cushion in the 69th and Suarez finally got on the scoresheet by converting from the penalty spot in the 75th.
The win keeps Barca top of the standings on 39 points from 18 games, three clear of second-placed Real Madrid who host Athletic Bilbao on Sunday. Sevilla are third on 34 after winning 2-0 at Real Mallorca.
"Whenever Messi gets the ball we are all on our feet to see what will happen, it's a real advantage to have him because at any moment Leo can appear and score a goal from any area," Barca coach Ernesto Valverde told reporters.
"They were starting to grow after their goal and the game could have turned dangerous for us but Messi scored and made everything easier for us."
After being unquestionably the second best team in Wednesday's goalless draw with Real Madrid, Barca were under pressure to not only beat Alaves but also to produce an exciting display of attacking football.
They looked intent on doing exactly that, as Vidal fired their first warning shot with a bicycle kick which Fernando Pacheco had to tip away and Messi put the ball in the net but was narrowly ruled offside.
Valverde brought Sergio Busquets back into the team after he had missed the game with Real due to illness and he also brought in academy product Carles Alena, benching Ivan Rakitic and Frenkie de Jong.
The changes helped Barca boss possession as their opponents focused on sitting deep and trying to defend, a plan which fell apart once Griezmann scored.
Alaves showed more ambition after the interval and after Pons had pulled them back into contention, Barca looked vulnerable, with keeper Marc-Andre ter Stegen losing the ball outside his box and scrambling to block a shot from Aleix Vidal.
Messi soon lifted the Catalans out of trouble, though, while Suarez's penalty brought up 30 league goals this season for Barca's front three, who have now scored more times between them than 18 La Liga sides.