The South American zone campaign for World Cup final places became tighter after Wednesday's matches with wins for Ecuador and Peru while Argentina could only draw at home to Paraguay.
Argentina, who opened the 10-country zonal qualifiers with five straight wins before losing 3-1 to Brazil still lead the way with 16 points from seven games.
But behind them, six teams, including struggling Brazil, are separated by just two points. The top four teams qualify automatically for the finals with the fifth-placed team going through to a play-off against the champions from Oceania.
Paraguay were once again the surprise packets as they held Argentina to a 1-1 draw in Buenos Aires.
Missing suspended goalkeeper Jose Luis Chilavert, the Paraguayans nevertheless again depended on a rock solid defence and on the art of the counterattack.
Against the run of play they took the lead in the 60th minute through Roberto Acuna, but the home side, minus star striker Gabriel Batistuta, hit back to equalise six minutes later through midfielder Pablo Aimar.
In the day's other matches, Ecuador moved into contention with a 2-0 home win over Bolivia, both goals coming from Agustin Delgado, while Peru kept their hopes alive with a 1-0 win over bottom club Venezuela.
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