Real Madrid clinched the LaLiga title in style as Rodrygo scored twice in a 4-0 thrashing of Espanyol.
Los Blancos needed only to avoid defeat to give third-placed Barcelona no chance of producing a remarkable turnaround in the title race.
And they made no mistake against Barca's city rivals on Saturday, Rodrygo doing the damage in the first half with a well-taken brace.
Marco Asensio made it 3-0 and Isco had a goal disallowed before Karim Benzema fittingly had the final say as Madrid claimed a 35th LaLiga title.
They will now turn their attention to trying to overturn a 4-3 deficit to Manchester City in the second leg of their Champions League semi-final on Wednesday in Spain.
Success this season represents a maiden LaLiga title for Ancelotti, who has become the first coach to win all of Europe's top five leagues, having previously triumphed in England, Germany, France and Italy.
Barcelona's poor performance
Madrid have led the way for much of the season as Atletico Madrid struggled to defend their title and Barcelona initially floundered without Lionel Messi.
Sevilla represented Madrid's closest rivals for a long stretch but fell off the pace, while Barca's recent poor run ended their slim hopes of a title challenge.
Espanyol started brightly with plenty of energy but they were fortunate not to go behind in the 13th minute when Mariano, playing as the central striker in place of the rested Benzema, hit the post with a header from point-blank range.
Mariano headed wide from Luka Modric's pass nine minutes later before the deadlock was broken by Rodrygo, who received Marcelo's cutback and stroked a side-footed effort into the bottom-right corner.
Ten minutes later, Rodrygo doubled their advantage, wrong-footing Diego Lopez with a clever finish after Espanyol lost possession deep in their own half.
Asensio effectively made sure of the points and the title 10 minutes into the second half, when he confidently finished off a rapid counter-attack led by Eduardo Camavinga.
Substitutes Benzema and Isco combined for what looked a fine fourth goal, only for the video assistant to intervene with Lopez's vision apparently impeded by an offside player.
It mattered not as Madrid regained the title they lost to Atletico last season, Benzema's 81st-minute effort too strong for Lopez to put the icing on the cake.