The Argentinian also passed a significant career milestone during the Tuesday fixture, scoring his 50th free kick, a stunner which hooped beautifully into the top-right corner.
Barcelona has a game in hand because the "clasico" against Real Madrid last weekend was postponed until December because of a separatist rally held in the Catalan capital.
Valverde's side have now won seven consecutive matches in all competitions, a run that began by beating Villarreal on September 24, when Messi returned from injury to make his first start of the season.
Ernesto Valverde eased him back into the line-up little by little and now he is back his normal self, as evidenced by his sublime performance in the 5-1 victory over Real Valladolid.
Barcelona took the lead after just two minutes when the ball bounced fortuitously to Lenglet in the area and he crashed an effort in off the crossbar.
Skipper Messi then doubled Barca's lead from six yards out on 58 minutes - his second goal of the campaign so far - while Suarez made it three eight minutes later as Messi unselfishly squared the ball for the Uruguayan while one-on-one with the 'keeper.
He told Catalunya Radio: "One day Messi will retire and Barca will cope with that".
Messi powered in a fourth and then set up Luis Suarez to sweep in a fifth.
Tuesday's other game saw Atletico Madrid draw 1-1 away to Deportivo Alaves.
In damage time, Messi ought to have had his hat-trick however curled broad of the left put up when he appeared sure to attain.
Gatti suggests that Messi - whose entire senior career has been spent with Barcelona - will not be able to compete with the likes of Cristiano Ronaldo, Diego Maradona and Pele without proving himself at another club.