MISSED the match? Catch Up via beIN SPORTS CONNECT | 2-WEEK free trial

Barca captain Messi made his 505th LaLiga appearance for the Catalan giant, drawing level with the club record set by Xavi, and reached 459 goals in the competition with a pair of stunning strikes.

At the other end of the scale, two players making their first LaLiga starts combined for the opening goal, Ilaix Moriba marking his league debut for Barca by setting up Francisco Trincao.

Luis Rioja pulled one back for Alaves in the second half but Trincao and Messi struck within 83 seconds of one another and Junior Firpo completed the scoring at the end of a wonderful move.

Barca struggled to create early openings, but after Marc-Andre ter Stegen got down to Rodrigo Battaglia's volley, it took the lead when Ilaix showed great composure with a patient cutback to tee up Trincao.

After seeing one goal chalked off by VAR (video assistant referee) for an offside against Antoine Griezmann after he'd seen a close-range shot saved, there was no doubt about Barca's second when Messi cracked a wicked 25-yard effort in off the post on the stroke of half-time.

Barca had looked vulnerable defensively and Rioja intercepted a pass from Ilaix and raced forwards to reduce the arrears with a confident finish before the hour mark.

Fernando Pacheco kept out Trincao but the Portugal international swept home the loose ball after Messi failed to round the Alaves goalkeeper after a sumptuous pass from substitute Pedri.

Messi made no mistake with his next chance, leaving Pacheco no chance with a fantastic left-footed effort that flew into the back of the net.

The Argentina international then scooped a pass over the defence for Griezmann, whose delivery across the face of goal was steered into the roof of the net by Junior.

Trincao slotted home another fine pass from Messi at the death but was denied his hat-trick by the offside flag.