Messi burst onto the scene after a quiet first hour as he dribbled past defenders in majestic fashion to double the Argentine lead in 65th minute, firing a left-footer from the box, that hit the left post before finding the net.
It took 26-year-old Messi eight years and 623 match minutes to earn his second World Cup goal, the first one coming in 2006 against Serbia Montenegro.
Debutantes Bosnia made a forgettable start as the conceded the fastest own goal in World Cup history in just two minutes and eight seconds but impressed as the game wore on with their fantastic defence, specially the way they managed to stifle Messi for most of the part.
Messi's last World Cup goal was in 2006 against Serbia Montenegro
A change of tactics in the second half revived Argentina, who had gone with a 5-3-2 formation but resorted back to 4-3-3. Substitute Vesad Ibisevic had the honour to score Bosnia's first ever World Cup finals goal, five minutes form the whistle, when he shot the ball in as Argentine goalkeeper Sergio Romero approached and failed to block.
At Porto Alegre, Karim Benzema hit a brace in France's 3-0 win over 10-man Honduras in a Group E game, where goal-line technology made its debut. At the start of the second half, a volley from Benzema, who had put his side ahead with a penalty conversion, hit post and bounced back into the area.
Honduras goalkeeper Noel Valladares tried to pull the ball out but referee Sandro Ricci declared it an own-goal after employing the new technology. Winston Palacios was handed a red card after two fouls on on Paul Pogba. Benzema scored his second goal in the 72nd minute from a difficult angle.