Barcelona came from behind at El Madrigal to defeat Villarreal 2-1 and keep their La Liga ambitions on track.
Samu Chukwueze had opened the scoring for the home side but Antoine Griezmann struck twice in the space of seven minutes to turn the result around.
It was his long ball down the touchline which allowed Antoine Griezmann to run clear on goal and delicately finish, a super assist.
And in his role as the right centre-back of a three, he was solid defensively too, winning 4/6 duels, both of his two tackles and both of his aerial challenges.
Alcacer managed just 13 touches of the ball as Barcelona marshalled him easily, and lost possession with five of those, completing just seven passes. He won 1/4 duels, none of his aerial challenges and had no shots at all in the game.
It just about sums up his season so far.
He duly scored, and that positivity took him into today where his deadly double made all the difference. He scored a quite brilliant effort similar to his goal here last season, delicately dinking the ball over the head of Sergio Asenjo from an acute angle.
And he also took advantage of Juan Foyth's suicidal backpass to intervene and roll neatly into the corner, and give Barcelona the win they needed to keep them in the hunt of Atletico Madrid in the table.