aBrazil beat Argentina 2-1 in their Copa America quarter-final last night after their opponents missed yet another penalty.

Argentine captain Roberto Ayala saw his kick saved by Brazil goalkeeper Dida after 78 minutes, throwing away a golden chance to level the score at 2-2.

Ayala took the kick after striker Martin Palermo, the first choice penalty taker, missed three penalties in the first-round match against Colombia.

Ronaldo scored the winner early in the second half with his fourth goal of the tournament as Brazil came from behind to beat their bitter rivals.

Juan Pablo Sorin had given Argentina an early lead with Rivaldo equalising from a free kick before half-time.

Sorin scored after 11 minutes with left-foot shot from outside the penalty area which ricocheted off a defender into the goal.

Rivaldo made his mark after 33 minutes when he floated a free kick over the Argentine wall from the edge of the area and into the top corner of the net.

Ronaldo fired Brazil in front three minutes after the interval with a low shot from outside the area after a neat passing move involving Emerson Ferreira and Ze Roberto.

Veteran Ivan Zamorano sent Chile into the last four, scoring a solo goal to give them a surprise 3-2 win over Colombia.

Zamorano's goal came after defender Pedro Reyes had twice headed Chile back on level terms after goals by Jorge Bolano and Victor Bonilla had put Colombia ahead.

Colombia had emerged as one of the competition's favourites after winning all three first-round games, their results including a 3-0 hammering of Argentina.

Their neat passing game, with more punch and bite than in the past, had also made them one of the competition's most entertaining sides.

Chile had qualified as one of the best third-placed teams after winning only one game in their group and had been criticised for their lacklustre displays.

They were without striker Marcelo Salas, serving the second game of a two-match suspension.

Mexico scored a last-gasp equaliser before knocking out Peru, while Uruguay ousted hosts Paraguay as Saturday's quarter-finals were decided on penalties.

Mexico, with two players suspended for doping and one for a red card, won the shoot-out 4-2 after a brilliant eighty-eighth- minute equaliser by Gerardo Torrado had forced a 3-3 draw with Peru.

Uruguay also came from behind to draw 1-1 with Paraguay, and then won 5-3 on penalties after Paraguay goalscorer Miguel Benitez missed his team's fourth kick.

Mexico played without midfielder Raul Lara and Paulo Cesar Chavez, who were suspended on Friday after failing a doping test following the match against Brazil, and key striker Cuauhtemoc Blanco, sent off against Venezuela.

Peru were great entertainment value, having previously won an enthralling encounter against Japan 3-2. However, they paid the penalty for relaxing when they were ahead.

Peru enjoyed a two-goal lead after 15 minutes thanks to Roberto Palacios, with a brilliant individual goal, and Jose Pereda, only to loosen their grip in midfield.

Two goals in four minutes by Luis Hernandez, the second from a controversial penalty, levelled the scores but Newcastle United's Nolberto Solano put Peru back in front in 41 minutes with another excellently taken goal from the edge of the penalty area.

The second half was equally as dramatic. Peru goalkeeper Oscar Ibandez made three outstanding saves to preserve his side's lead while at the other end, the Peruvians squandered several chances to make the game safe.

Then, with two minutes left, a poor Peruvian clearance fell at the feet of Torrado, who scored with a powerful drive from 25 yards out.

Mexico, who were knocked out of the 1986 and 1994 World Cups on penalties, converted all four of their kicks, while their flamboyant goalkeeper, Jorge Campos, wearing yet another outrageous kit, did not have to make a save.