Peru produced a shock 3-0 win over Uruguay while Bolivia twice fought back to draw 2-2 with hosts Venezuela in a dramatic opening to the Copa America on Tuesday.
Venezuela also had an injury-time penalty turned down as the tournament began under the watchful eye of President Hugo Chavez, the self-styled leftist revolutionary.
Chavez, flanked by Diego Maradona on one side and his close ally President Evo Morales of Bolivia on the other, was in San Cristobal to watch the official opening ceremony and Venezuela's first match.
"Today, nobody will lose, we will all win, because this is the same country, our South America, our America," said Chavez, who has warned of a plot by his opponents to sabotage the tournament.
Although the ceremony took place before the Venezuela-Bolivia game, the tournament had already kicked off with Peru's upset win over Uruguay in Merida.
Peru's impressive attacking force of Jefferson Farfan, Claudio Pizarro and Paolo Guerrero belied the team's reputation for ineffective football as they sliced through the Uruguayan defence in the Group A opener.
The Peruvians also matched the Uruguayans for tenacity as the tackles flew in from both teams.
Miguel Villalta headed Peru into the lead in the 27th minute from Farfan's cross before substitute Juan Carlos Marino surprised Fabian Carini as he whipped in the second in the 73rd.
Guerrero tapped in the third following good work by Andres Mendoza.
That goal was missed by millions of television viewers as the Venezuelan networks transmitting the game had cut to the opening ceremony in San Cristobal without any warning.
Venezuela twice led with goals from Giancarlo Maldonado in the 21st minute and Richard Paez in the 56th.
But an own goal by Alejandro Cichero put Bolivia level at halftime and Juan Carlos Arce's 84th-minute equaliser deprived Venezuela only their second win in the tournament's history.
The Venezuelans claimed a penalty when Jorge Vargas was upended by Gualberto Mojica in injury-time but a goal kick was awarded.
Elsewhere, Brazil pair Robinho and Diego both promised that they were ready to replace Kaka and Ronaldinho, who said they were too tired to play at the tournament.
"It's the time for our generation. I know that if Brazil don't do well, the criticism will rain down upon me," Robinho told reporters in Puerto Ordaz, where Brazil face Mexico in Group B on Wednesday.
"We are more mature and have more experience after playing for European teams."
The match comes at a difficult time for Mexico coach Hugo Sanchez after his team lost 2-1 to the United States in the Gold Cup final on Sunday.
"As a player, the same thing happened to me, I needed time to triumph in Europe and now it's the same, be patient," the former Real Madrid coach told reporters.
The Mexicans have also been hit by rumours of splits in the squad.
The match, the second half of a double bill, is preceeded by Chile and Ecuador.
Chile coach Nelson Acosta admitted he was concerned about the recent form of midfielder Matias Fernandez and might rest the Villareal player.