Argentina and Chile's World Cup qualification hopes were left on a knife edge Tuesday after the South American heavyweights slipped up once again on the road to next year's finals in Russia.

Argentina needed a second-half own goal to help them snatch a 1-1 draw against already-eliminated Venezuela in Buenos Aires while Chile crashed to a 1-0 defeat against Bolivia in La Paz.

The results left 2014 World Cup finalists Argentina and reigning Copa America champions Chile outside of the automatic qualifying places and sets up a nail-biting final two rounds of matches next month.

Argentina are fifth in the standings with 24 points from 16 games while Chile are sixth with 23 points.

The Argentinians -- who would face a playoff against New Zealand if they remain fifth -- host fourth-placed Peru next month in Buenos Aires before an awkward final game at altitude against Ecuador.

Argentina would still be favourites to progress to Russia past the New Zealanders, but will be taking nothing for granted in their final two qualifiers next month after another disjointed performance.

Chile meanwhile will face Ecuador in Santiago on October 5, before heading to Brazil for their final qualifier five days later.

At the top of the table, Brazil have already qualified and assured themselves of first place. The Brazilians picked up another point on Tuesday with a 1-1 draw against third-placed Colombia in Barranquilla.

A spectacular volleyed goal from Willian gave the Brazilians the lead on the stroke of half-time before Colombia clawed back a share of the points with a battling second-half display capped by a headed equaliser from Radamel Falcao.

- 'We must fight' -

In Buenos Aires, Argentina coach Jorge Sampaoli admitted his team had blown a golden opportunity to force themselves into the automatic qualifying places following Chile's defeat earlier in the day.

Sampaoli blamed poor first-half finishing for his side's failure to take all three points against the Venezuelans.

"We have two games left against Peru and Ecuador and we need to win both of them," Sampaoli said. "We had three chances to score in the first half and everything could have been settled."

"We must continue to fight in attack and give strength to the players."

Chile coach Juan Antonio Pizzi echoed Sampaoli's sentiments after watching his side slide to a dispiriting loss in La Paz.

"We will fight, we will make the greatest effort possible, we believe that we have the ability to compete with the best and we will try to obtain the results that allow us to qualify," said Pizzi.

Although Chile have a difficult run-in against Ecuador and Brazil, Pizzi said his side had not lost hope.

"There are two matches left, I'm going to fight and my players are going to fight, with all the force we have," Pizzi said.

- Uruguay on brink -

Uruguay meanwhile moved to the brink of qualification with a typically combative 2-1 win over Paraguay in Asuncion.

Paraguay, riding high after a brilliant 3-0 win over Chile in Santiago last month, were left stunned by two opportunistic Uruguay goals.

Federico Valverde fired Uruguay into the lead with a deflected shot on 76 minutes before Luis Suarez then broke clear to set up the visitors second.

The Barcelona superstar rounded goalkeeper Anthony Silva and then saw his shot hit the woodwork only to rebound into the net off Gustavo Gomez.

Angel Romero pulled a goal back for Paraguay but hopes of a dramatic late fightback came to nothing.

The result leaves Uruguay second in the standings with 27 points from 16 games. A win in Venezuela in their next game would see them through to the finals.

Seventh-placed Paraguay still have an outside chance of qualification but will probably need to beat Colombia in their next game before wrapping up their campaign against Venezuela.

Argentina's Lionel Messi reacts at the end of their 2018 World Cup qualifier football match against Venezuela in Buenos Aires. Photo: AFP

Standings in 2018 World Cup South American qualifying competition after latest matches (played, won, drawn, lost, goals for, against, points):

Brazil 16 11 4 1 38 11 37

Uruguay 16 8 3 5 28 18 27

Colombia 16 7 5 4 19 16 26

Peru 16 7 3 6 26 25 24

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Argentina 16 6 6 4 16 15 24

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Chile 16 7 2 7 24 23 23

Paraguay 16 6 3 7 17 23 21

Ecuador 16 6 2 8 24 24 20

Bolivia-x 16 4 1 11 14 34 13

Venezuela-x 16 1 5 10 18 35 8

Note: Top four teams qualify automatically for 2018 World Cup. Fifth place team plays intercontinental playoff vs New Zealand.

X-eliminated