Messi’s pre-game departure — reportedly to prepare for his wedding — prompted grumbles among fans but Argentina were not short of firepower as six different players found the net.
Defender Federico Fazio and Carlos Correa scored in the first half before Alejandro Gomez, Leandro Paredes, Lucas Alario and Angel di Maria poured on the goals in the second half.
Argentina, who were also missing Gonzalo Higuain and Nicolas Otamendi, were in control in the outset but it took until the 24th minute before Fazio flicked in a header from a corner.
Argentina grabbed their second five minutes later, with Sevilla striker Carlos Correa tapping in at the near post from a cross from Juventus’s Paulo Dybala.
Argentina cut loose after the hour-mark, scoring their last four goals — while outclassed Singapore, 159th in the FIFA rankings, didn’t manage a shot on target all night.
The absence of Messi had prompted anger with social media users demanding ticket refunds, while Singapore’s head coach called his withdrawal “unfortunate”.