Santiago, Oct 9 (IANS): Eduardo Vargas and Alexis Sanchez scored second-half goals as Chile overcame Brazil 2-0 while Ecuador sprang a surprise snatching their first qualifying triumph on Argentinian soil in seven attempts, courtesy of late strikes by Frickson Erazo and Felipe Caicedo in the opening 2018 World Cup qualifying round.

Vargas struck in the 72nd minute with a first-time volley that slipped through the hands of goalkeeper Jefferson after Mauricio Isla's free-kick on Thursday, reports Xinhua.

Sanchez then put the result beyond doubt at the Estadio Nacional stadium by playing a one-two with Arturo Vidal and drawing Jefferson off his line before firing into an unguarded net.

"It's an important step because Brazil have a great record against us in World Cup qualifiers," Chile coach Jorge Sampaoli said.

"On a personal level it's a great feeling because I had never beaten Brazil before tonight. To beat a five-time World Cup champion is a a big result for Chile."

In Buenos Aires, Frickson Erazo and Felipe Caicedo were on target as Ecuador surprised Argentina with a 2-0 win at the Monumental stadium on Thursday.

It was Argentina's first loss in 40 qualifying matches in Buenos Aires, a run stretching back to the famous 0-5 defeat to Colombia in 1993.

"I'm having a job finding anything positive to take away from the game," lamented Argentina coach Gerardo Martino after the match on Thursday.

"Ecuador were superior to us in every department."

In a hapless night for the hosts, Manchester City striker Sergio Aguero was carried off on a stretcher in the 24th minute with an apparent hamstring injury.

In other South American zone qualifiers on Thursday, Uruguay won 2-0 away to Bolivia, Colombia beat Peru 2-0 at home and hosts Venezuela lost 1-0 to Paraguay.