Lionel Messi put his weekend penalty miss behind him with two goals for Argentina in Hong Kong before treating a pitch invader to an autograph.
Messi emerged from the bench to score twice in Argentina's 7-0 annihilation of Hong Kong before he was politely accosted by an overzealous supporter brandishing a pen.
The Barcelona forward duly obliged and signed the fan's shirt.
Coach Gerardo Martino overhauled his starting line-up from the Brazil defeat on Saturday, and it proved to be a one-sided affair with Gonzalo Higuaín, Messi and Nicolás Gaitán all netting doubles to add to Éver Banega's opener.
Messi hopes the team can keep building under his former coach at Barca, Martino, who only took charge in August.
"Argentina always have the obligation to win," he said. "We had to take our opponents seriously, despite the gap, and I think we played well and were professional.
"Now it is time for us to settle under the new boss. We have to understand Martino's ideas as quickly as possible in order to progress.
"We have the Copa America ahead and there is nothing more important. The World Cup is part of the past, we came close but now we want to win the Copa America."