Robert Lewandowski was the star of the show, scoring a hat-trick that saw Barça bounce back from their defeat to Osasuna last week.
The game got off to an eventful start as Barça dominated the early moments.
In the fourth minute, a goal by Lamine Yamal was ruled out for offside, and just two minutes later, Ferran Torres was forced off with a hamstring injury, replaced by Eric García.
But moments later, Lewandowski headed in Raphinha’s cross to give the visitors the lead.
Alavés tried to fight back, pressing high, but Barça capitalised on the open spaces.
Raphinha’s brilliant solo run led to an easy tap-in for Lewandowski to double Barcelona’s lead.
Just before the half-hour mark, Eric García’s assist gave Lewandowski time and space to complete his hat-trick with a composed finish into the bottom corner.
Alavés thought they had pulled one back when Toni Martínez headed in just before half-time, but the goal was ruled offside. Barça took a commanding 3-0 lead into the break.
The second half saw Alavés threaten as they hit ... and forced Barça into several defensive scrambles.
Toni Martínez and Kike García both came close to scoring, but Barcelona’s defence held firm.
Substitutions by Hansi Flick, including Ansu Fati and Frenkie de Jong, helped steady the ship as Barça saw out the match, keeping a clean sheet.
With this win, Barça remain three points clear at the top of La Liga, and Lewandowski’s stellar form continues to drive their success. Tough tests against Bayern Munich and Real Madrid await after the international break.