Bolivia served up an early surprise in the opening match of the Copa America as they held hosts Argentina to a hard-fought draw in La Plata.
Argentina had to battle back from Edivaldo Rojas' 47th-minute opener for the visitors, finally drawing level 14 minutes from time when substitute Sergio Aguero tucked home a sweet volley.
The hosts were the overwhelming favourites heading into the Group A encounter, despite suffering a 6-1 reverse to Bolivia in their last meeting in April 2009, when the extreme altitude in La Paz undoubtedly played a key role in the one-sided outcome.
On home soil, Sergio Batista's men were tipped to dominate and duly spurned a number of clear-cut chances, including one in the very first minute when Carlos Tevez produced a poor header when in a good position.
Ezequiel Lavezzi fired wide for Argentina in the 24th-minute, while on the half-hour Tevez again had a good opening but Bolivia goalkeeper Carlos Erwin Arias made the save.
Esteban Cambiasso was also guilty of wasting a good chance when he miscontrolled in the area, and Argentina were soon made to pay for their lack of cutting edge as Bolivia went ahead three minutes into the second-half.
The goal was far from a thing of beauty when it did arrive, Rojas connecting weakly with a corner kick to steer the ball inside the near post, where Ever Banega should have done better with his attempted clearance.
The goal appeared to rattle the hosts for a time, with Lavezzi guilty of throwing away good attacking positions with woeful crosses from the right wing.
Argentina's fortunes turned on the 70th-minute introduction of Aguero, who replaced the ineffective Lavezzi and quickly set about getting his side back on level terms.
The Atletico Madrid striker's big moment arrived just minutes later, Aguero setting himself perfectly to volley brilliantly into the far corner after being teed up by Nicolas Burdisso's chest-down.
Argentina had the best of what chances there were in the final minutes, but in the end the hosts will have been happy to escape with a point after a disjointed display.
Colombia and Costa Rica are the other teams in Group A and meet in the second game of the tournament on Saturday.