Sabella took decisive action at half-time, sending on Higuain and Fernando Gago for Maxi Rodriguez and Hugo Campanaro and reverting to the tried and tested 4-3-3.
Initially it was Bosnia who continued to press, with Hajrovic twice working Romero from range.
But Messi was beginning to see more of the ball, and he twice teed up Aguero, who blazed wildly over before testing Asmir Begovic with a side-foot shot.
A ballooned free-kick suggested that Messi was still feeling his way into the tournament, but moments later he announced his arrival in style with Argentina's second goal -- his first World Cup goal since 2006.
Ibisevic reduced the arrears with five minutes to play, squeezing a shot between Romero's legs and over the line, but Argentina managed to see the game out.
"We had to the misfortune to score an own goal," said Bosnia coach Safet Susic. "When you play Argentina, you have to play well and have luck.
We still have two games to go." The Barcelona superstar created the thi