The goals continued to rattle in across Brazil. France cruised to a 3-0 victory in Porto Alegre, and in the other Group E match, Switzerland came from behind to beat Ecuador 2-1 with a dramatic, counter-attacking winner in injury time. (Agencies)
The buildup to the fourth day of action at the 2014 World Cup had all been about Messi, the 26-year-old Barcelona forward who has lit up club soccer like few others but has so far failed to repeat those heroics on the biggest stage of all.
His last World Cup goal came on June 16, 2006, the sixth out of six Argentina put past Serbia & Montenegro in Germany.
Messi's roar of delight after a fine left-foot strike from the edge of the area on Sunday suggested the goal would lift a huge weight from his shoulders.
"It was important to start with a win and to get three points, but we need to improve," Messi said after also being named man of the match in the 2-1 victory in Group F.
Until that point Messi's display had been lacklustre, but it proved a crucial goal when Bosnia scored late on to set up a tense end to a game many had expected Argentina to win easily.
There was a touch of fortune in the outcome, after Bosnia's Sead Kolasinac netted the fastest own goal in World Cup history in the third minute.
His side recovered from the shock and began to look the better team, but a lack of composure in front of goal saw several long-distance efforts fly high and wide.
Messi's successor as World Player of the Year, Cristiano Ronaldo, expects to start for Portugal against Germany in the pick of Monday's matches.
The 29-year-old said he was fit for the Group G encounter in Salvador, despite struggling with tendinosis in his left knee.
Asked whether a great World Cup was all that was missing from a glittering career, he replied: "I don't think I have to show anyone anything. If you look at my statistics and my resume... I have no words for that question.”
"I think I do not have to demonstrate anything, not now, before, not after. What I have to do is just continue my career, which has been great so far," he said.
In the other Group G clash, Ghana meet the United States in Natal, while Iran and Nigeria play in Curitiba in Group F.
In Porto Alegre, France survived a bruising encounter with Honduras, but passed the test with aplomb in a game where Benzema grabbed two and goal-line technology was used to confirm the ball had crossed the line for the first time at a World Cup.
Benzema's shot hit the upright and the ball rolled across the goal, only for Honduras keeper Noel Valladares to divert it over the line by inches.
Honduras were reduced to 10-men after Wilson Palacios charged into French midfielder Paul Pogba seconds before the break in a challenge that earned him a second yellow card.
Benzema stroked home the resulting penalty, and 18 minutes from time he struck again from a narrow angle, earning a rendition of "La Marseillaise" from the red, white and blue clad French fans.
The result will have delighted France coach Didier Deschamps, especially after Les Bleus' 2010 debacle in South Africa when they failed to win a game amid bitter squabbling that blew up into a national scandal.
In arguably the most exciting contest of the day, substitute Haris Seferovic finished off a breathtaking box-to-box counter-attack in stoppage time to give Switzerland a 2-1 win over Ecuador in Brasilia.
A brilliant block tackle by Valon Behrami in his own area instigated the break, which was allowed to continue by an excellent decision from Uzbek referee Ravshan Irmatov after the midfielder was body-checked.
With more than three goals a game on average, and a surprisingly expansive style of soccer for the early stages of a World Cup, action on the field has grabbed people's imagination in a country considered by many to be the sport's spiritual home.
The tournament has gone much more smoothly than many had expected, with protests against the $11 billion spend on new stadiums and infrastructure small compared with mass demonstrations that rocked Brazil a year ago.
On Sunday, police blocked a small group of anti-World Cup protesters who were trying to reach the Maracana stadium before the Argentina-Bosnia game.
About 150 bandanna-clad demonstrators carrying banners that said "FIFA go home" marched towards the stadium, but police on horseback blocked their path, leading to minor scuffles.
A similar-sized march was held ahead of the Switzerland-Ecuador game, but participants simply laid down their banners in front of a police cordon and dispersed when the game started.
The goals continued to rattle in across Brazil. France cruised to a 3-0 victory in Porto Alegre, and in the other Group E match, Switzerland came from behind to beat Ecuador 2-1 with a dramatic, counter-attacking winner in injury time.