World champions Argentina made it three wins out of three in South American World Cup qualifying with a hard-earned 1-0 win over a determined Paraguay on Thursday.

A third-minute goal from Nicolas Otamendi was just enough for Lionel Scaloni's team, with Lionel Messi coming off in the bench in the second half and hitting the woodwork twice.

Darwin Nunez struck a stoppage time penalty as Uruguay fought back for a 2-2 draw with Colombia in Barranquilla while Ecuador got their first points with a last gasp 2-1 win at Bolivia.

Messi's fight for full fitness inevitably dominated the build-up to Argentina's attempt to maintain their 100% record and the seven-time Ballon d'Or winner started on the bench with Julian Alvarez and Lautaro Martinez leading the attack.

But it was veteran defender Otamandi who provided the moment of attacking inspiration, meeting a Rodrigo De Paul corner with a brilliant volley at the back post.

Atletico Madrid midfielder De Paul went close to doubling the lead three minutes before the break when he struck the post and moments later Nicolas Gonzalez fired just wide.

Messi replaced Alvarez in the 53rd minute as Scaloni looked to break down a disciplined and well organised Paraguay side but the woodwork foiled their talisman.

Argentina's defender Nicolas Otamendi (3rd L) celebrates with teammates after scoring the all-important goal during the 2026 FIFA World Cup qualifier match against Paraguay at the Mas Monumental stadium in Buenos Aires, on October 12, 2023. PHOTO: AFP

An inswinging corner from the right almost snuck in, but struck the post and then, after winning a free kick on the edge of the box, Messi curled his shot against the same post.

Colombia paid the price for squandering a series of chances to put the game to bed after taking a 2-1 lead in the 52nd minute through Mateus Uribe.

James Rodriguez put Colombia ahead in the 35th minute, bringing down a cross from Santiago Arias with his right foot and then drilling home with his left.

Uruguay drew level just a minute after the restart when Mathias Olivera was left unattended to head home a Nicolas de la Cruz corner.

But Colombia restored their lead when Luis Diaz burst inside from the left flank and fed Rafael Borre, whose low cross was tucked home by Uribe.

Luis Diaz then missed a glorious chance for a third when he was sent through, one on one, with the goalkeeper but scooped his shot high over the bar.

Rodriguez saw a low shot from inside the box strike the post and a minute later fed Jhon Arias, who clipped his shot against the bar.

Uruguay escaped with a point after Colombia goalkeeper Camilo Vargas rushed off his line and collided with Maximiliano Araujo.

Vargas was dismissed for a second yellow card and Liverpool striker Nunez kept his cool to bury the penalty and give Marcelo Bielsa's side a precious point.

Kendry Paez, the 16-year-old Ecuadorean prodigy, became the youngest player to score in a CONMEBOL World Cup qualifier when he put his team ahead against Bolivia in La Paz with a composed finish in the 45th minute.

A great shot on the turn from Rodrigo Ramallo levelled for Bolivia before a defensive lapse allowed Kevin Rodriguez to grab the winner for Ecuador in the sixth minute of stoppage time to leave Bolivia still without a point.

Brazil, having won their opening pair of games, hope to continue their positive start against Venezeula later on Thursday while Chile host Peru.