Messi, four-times world player of the year and Argentina's best footballer since Diego Maradona graced the 1986 tournament, put his side 2-0 ahead on a night when the stadium was turned into little Buenos Aires by tens of thousands of his countrymen.
"It was important to start with a win and to get three points but we need to improve," man-of-the-match Messi told reporters.
Although they took the lead in the third minute when Sead Kolasinac netted the fastest own goal in World Cup history, Argentina looked unconvincing until Messi struck with a dazzling run and sweet left-foot shot that went in off the post in the 65th minute after a one-two with substitute Gonzalo Higuain.
It was Messi's first goal in the finals since scoring in Argentina's 6-0 win over Serbia & Montenegro almost eight years ago to the day.
Even then they could not afford to relax as Bosnia substitute Vedad Ibisevic scored in the 85th minute to set up a tense finale.
"They were two different halves," Argentina coach Alejandro Sabella told a news conference.
"In the first one I think we controlled the Bosnians well, but beyond that, we didn't create the kind of depth that we managed in the second half. Obviously we need to improve," he said.

READ MORE: Messi ends eight-year World Cup goal drought
The match was the first game in the tournament to be played at the Maracana, which on Monday celebrates the 64th anniversary of its official opening at the start of the 1950 World Cup.
It was ironic that it was Argentina celebrating in party-style as they just about lived up their billing as odds-on favourites to qualify from a group which also includes Iran and Nigeria and keep alive their hopes of a third world title.
The match began dramatically when Kolasinac put through his own net after two minutes eight seconds, beating the previous unwanted record set by Paraguay's Carlos Gamarra against England in 2006 by 38 seconds.
He was in the wrong place when a Messi free kick, headed on by Marcos Rojo, hit him and went in.
Bosnia, naturally shaken after making such a bad start to their first ever match in the finals, did not dwell on their misfortune for long.

After surviving a nervy spell, they began to look the better side against a subdued Argentina team who were in danger of losing their record of winning their opening match in their last five World Cups.
Messi, whose tepid displays in the last World Cup in South Africa when he failed to score were exhaustively documented, made little impression until his goal and Bosnia had their chances with both Senad Lulic and Edin Dzeko going close in the first half.
Substitute Ibisevic earned a place in Bosnian soccer folklore by scoring their first World Cup goal when he placed his angled shot through Sergio Romero's legs, but it was too little too late.
Bosnia were far from outplayed, however, and capitalised on a cautious safety-first approach from Sabella in the first half.
Playing with five at the back against lone striker Dzeko and with Sergio Aguero and Messi getting limited service in attack, Bosnia dealt with their more illustrious opponents with relative ease.
Muhamed Besic did a good policing job on Messi who was largely anonymous in the first half.
Sabella changed his formation at halftime, introducing Fernando Gago in midfield and Higuain in attack but in the end it was Messi's magic, as so often is the case, that made the difference.
"The objective was to play as well as we can against Argentina, who are the favourites to win the World Cup, and I think we played a good match," Bosnia coach Safet Susic said.
"We played well in both halves and it was only because of the psychological pressure that we looked as if we had run out of steam a little bit in the closing stages," he said.    

Argentina must do better after narrow Bosnia win: Sabella    

Argentina must improve on Sunday's unconvincing 2-1 win over World Cup debutants Bosnia if they are to make a serious mark on the tournament, coach Alejandro Sabella said.

The twice world champions struggled to live up to their billing as one of the favourites, especially in the first half of their opening Group F match when they looked unadventurous with five defenders on the field.
They were helped by an early own goal from Sead Kolasinac before Lionel Messi lit up the game in the second half with a signature goal in front of thousands of Argentina fans in the Maracana stadium in Rio de Janeiro.
Sabella said he took heart from Argentina's more creative play once he scrapped his ultra-cautious starting selection at halftime and brought on striker Gonzalo Higuain and midfielder Fernando Gago to give the team more firepower.
"Obviously we need to improve and some of that improvement falls to me," he told reporters, saying he rated Argentina's performance as a six-out-of-10.
"In the first half, I think we controlled the Bosnians well but beyond that we didn't create the kind of depth that we managed in second half."
Sabella told his players at halftime to pass more to Messi and to give him more options when he was on the ball. The advice paid off in the 65th minute when Messi exchanged passes with Higuain and unleashed a crisp shot that went in off the post.
"I think Messi is the best player in world, regardless of what happens in this World Cup, and he's among the best ever players in the history of football, regardless of what happens at this World Cup too," Sabella said.
The diminutive striker agreed that Argentina's performance was not good enough and voiced his frustration at not getting enough of the ball.
"In the first half, it was difficult, because we were playing deep and we let them play. I was alone and it was very difficult," Messi told reporters.
"We need to improve but the best thing is the result. It is not easy to play the first match at the World Cup with all the nerves and the pressure," he said.


Latest News from Sports News Desk