Lionel Messi, Argentina, Chile, World Cup, South American qualifiers
Lionel Messi celebrates after scoring the winning goal for Argentina in their qualifier against Chile, March 23, 2017Reuters

Lionel Messi was the decisive man again as Argentina climbed above Chile and into the automatic places for the 2018 World Cup in Russia with a hard-fought win, while leaders Brazil continued to impress, thumping second-placed Uruguay in the South American WC qualifiers on Thursday.

In an extremely important game for both teams, Argentina were the ones who came away from Buenos Aires with a smile on their faces, thanks to a solitary goal from Messi, who netted from the penalty spot in the 16th minute.

Chile, tried and tried, but just could not muster up the opportunity that found the back of the net.

As a result, they not only lost their place in one of the four automatic qualification spots, they are now down to sixth in the table, which, if the qualifiers were to end today, would have seen them miss the plane to Russia completely. The top four automatically qualify, while the fifth-place team plays an inter-continental playoff.

Brazil extended their lead at the top of the South American standings with an emphatic 4-1 win over Uruguay.

Paulinho was the man in the spotlight after the match, with the former Tottenham midfielder scoring a hat-trick. Neymar, of course he did, scored the other goal, with Uruguay getting their consolation strike through Edinson Cavani, who actually started off the scoring in the match with a ninth minute penalty.

However, Brazil roared back with Paulinho's first in the 18th minute, before three goals in the second half blew Uruguay away.

Colombia also picked up a much-needed win, topping Bolivia 1-0, thanks to a late goal from their main man James Rodriguez.

Paraguay pulled off a bit of a surprise when they beat Ecuador 2-1. Bruno Valdez and Junior Alonso put the home team in a 2-0 lead, and while a Felipe Caicedo spotkick reduced the deficit in half, Ecuador could not find the equaliser in time.

In the final game of the round of matches on Thursday, Venezuela and Peru played out an entertaining 2-2 draw.

After all the results, Brazil now have a seven-point cushion at the top, further enhancing their dominance in the qualifiers this time around.

Uruguay remain in second place on 23 points, with Argentina, on 22 from 13 matches, climbing from fifth to third. Colombia are now fourth on 21 points, while Ecuador and Chile have 20 each. Paraguay aren't far behind on 18, with Peru a further three points adrift.

Bolivia and Venezuela are out of contention, having managed just seven and six points respectively, with five matches to play.

Results: Argentina 1-1 Chile; Colombia 1-0 Bolivia; Paraguay 2-1 Ecuador; Uruguay 1-4 Brazil; Venezuela 2-2 Peru.