Bacra was held to a scoreless draw in a bad-tempered match at city rivals, Espanyol, last weekend.
But the diminutive Argentine had his shooting boots with him at the Nou Camp Saturday to ensure there would be no repeat failure to score against one of La Liga's lesser lights.
Neymar put a cap on proceedings by adding a fourth late on but he could do little to outshine his South American strike partner.
Messi is hoping to claim the FIFA Ballon d'Or prize -- the coveted title awarded each year to the world's best player -- for a fifth time when it is handed out on Monday.
And it took him just eight minutes to remind the judges of his scoring qualities as he deftly guided Arda Turan's low cross past Andres Fernandez in the Granada goal.
Messi and Barca's second arrived six minutes later after another low cross, this time for strike partner Luis Suarez.
And Messi made it three when Neymar's shot rebounded off the post into his path six yards out on 58 minutes.
Neymar rounded off the scoring with seven minutes remaining, clipping the ball into the roof of the net after Alexi Vidal's low cross missed everyone to arrive invitingly at the back post.
Speaking to reporters after the match, Barca coach Luis Enrique described Messi as a "unique player" not just for his individual genius but for his willingness to sacrifice for the team.
"Team goals motivate him year on year," Enrique said. As for performances among the rest of his side, he added, "I thought (they) looked good I am very happy with the players."
The win took Barcelona back to the top of the Spanish standings, but Atletico Madrid's 2-0 at Celta Vigo Sunday saw Diego Simeone's return to the top of the table.
Second half goals from Antoine Griezmann and Yannick Ferreira-Carrasco gave Atletico another vital win, leaving it two points clear of Barca, but having played a game more.
Real Madrid is third, four points adrift, with Villarreal a further point behind after a 2-0 home win over Sporting Gijon, thanks to a Cedric Bakumbu double.
Griezmann made the breakthrough just after half time after a slick passing move, his 10th goal of the season, while Ferreria-Carrasco scored in the closing moments to seal the win against fifth placed Celta.