The Argentinians were far below their best in the first half, but responded in the second to move within two points of Paraguay and Brazil ahead of them in the standings.

Colombia meanwhile were unlucky losers, as they needed just 60 seconds to create their first chance when Radamel Falcao Garcia forced goalkeeper Mariano Andujar to divert his shot out for a corner.

Soon after Andujar was called into action again to save a long-range shot by Vladimir Marin and to stop Wason Renteria when he went one-on-one with the goalkeeper.

Then shortly after the half hour mark Falcao came close with a volley from outside the box.

Argentina did not respond until the 52nd minute when Lionel Messi crashed a free kick onto the crossbar, then three minutes later they went in front when Diaz met Juan Sebastian Veron's corner with a volley to score at the far post.

Falcao again and Camilo Zuniga had chances to level the game for Colombia, but in the end Argentina's talented midfield held on to the ball to protect their slender lead.

"I'm happy with the result, but we can't repeat the performance we gave in the first half," said Argentina coach Diego Maradona.

"I was furious in the first half because they were stealing the ball off us easily. We weren't focused."

Colombia are eighth with 14 points, three behind Uruguay, who are in the last qualifying place.

Next Wednesday, Argentina take on Ecuador in the height of Quito without captain Javier Mascherano who will be suspended after picking up a yellow card.