Three days after marking his return from a three-month international ban by scoring the winner against Brazil, Messi once again underscored his value to his country.
Argentina had dominated the early exchanges and came close to breaking the deadlock in the 13th minute when Paulo Dybala had a shot blocked in a crowded box.
Uruguay lost defender Sebastian Coates to an apparent hamstring strain shortly afterwards but they continued to grow into the game with Suarez asserting his presence.
The Uruguayans' patience was rewarded in the 34th minute when Suarez knocked on a superb cross by Lucas Torreira and Cavani had the easy job of poking the ball over the line.
Dybala had the ball in the net four minutes later but it was ruled out for a clear handball, and Messi ended the first period by forcing a save from Martin Campana before setting up Rodrigo De Paul who missed a golden chance.
In a low-key start to the second half, Messi continued to pull his side's strings but there were few chances of note until just past the hour mark, when his free-kick found Aguero to equalise.
Five minutes later Suarez netted to put Uruguay back in front, and despite Argentina's attacks through Dybala and Aguero, Oscar Tabarez's side looked set to hold firm.
When Aguero headed over in the 90th minute it appeared Argentina's last chance had gone, but when the ball struck Caceres' arm in the fourth minute of added time, Messi took the chance to earn a draw.