Host Paraguay was held to a 0-0 draw by underdog Bolivia while surprise guests Japan gave Peru an early fright before going down, 3-2, as the Copa America began tonight.
Paraguay, expected to use home advantage to help them challenge for a third Copa America title, were jeered off the field by a crowd of 40,000 after their scoreless stalemate against Bolivia.
The Paraguayans repeatedly threatened to breach the Bolivian wall in the first half but ran out of ideas after Coach Ever Almeida, already under pressure for forcing a fish-only diet on his squad, took out Nelson Cuevas and Hugo Ovelar, two of his most creative players, at halftime.
The coach further angered the crowd when he replaced 17-year-old striker Roque Santa Cruz, the great hope of Paraguayan soccer, midway through the second half.
"We did everything well until we got to the last 20 meters of the field," said Almeida, whose team plays Japan on Friday.
Earlier, Peru had kicked off the competition with a far more lively game against Japan, which had been invited to take part by the South American Football Confederation.
Japan scored the first goal of the South American tournament when Brazilian-born striker Wagner Lopes headed in at the near post following a free kick in the seventh minute.
Japan then held out against Peruvian dominance until the 71st minute, when Jorge Soto scored from a narrow angle.
Three more goals followed in the next 11 minutes. Roberto Holsen put the skillful Peruvians in front, Atsuhira Miura equalized from a free kick and Holsen then scored the winner, finishing off an excellent move involving Nolberto Solano and Flavio Maestri.
"We made some small mistakes, which at this level proved costly," said Japan Coach Philippe Troussier.
The tournament continues Wednesday with the group B games between champions Brazil and minnows Venezuela, preceded by a meeting between Mexico, another outside team taking part as a guest, and Chile.