Full-back Baltazar Amaya scored a brace of tries as Uruguay kept their faint Rugby World Cup quarter-final hopes alive with a bonus-point 36-26 victory over ill-disciplined Namibia on Wednesday.

Namibia led 20-12 at half-time but paid for their indiscipline in the second half as prop Johan Coetzee and captain Tjiuee Uanivi were yellow-carded, while replacement prop Desiderius Sethie saw red.

Uruguay could still make the knock-out stages after their first win in three Pool A matches, but it would take a highly improbable victory over New Zealand next week to do so.

The Namibians got off to a dream start inside the first minute.

Uruguay spilled the ball in midfield and right wing Gerswin Mouton scooped it up before streaking away to score under the posts.

Ten minutes later, quick hands from Namibia sent JC Greyling scampering down the left wing to dot down in the corner, with fly-half Tiaan Swanepoel converting both.

Uruguay soon hit back as Amaya scored his first try, blasting through Namibia scrum-half Damian Stevens. Felipe Etcheverry missed the conversion and Swanepoel punished him with a penalty soon after.

Both teams looked willing to run the ball but Uruguay had a clear advantage in the set-piece and used it well to drive over hooker German Kessler from a line-out maul.

Etcheverry kicked the conversion from wide on the left but Swanepoel landed another penalty to give Namibia a 20-12 half-time lead.

The second half was a different story as Namibia paid for their poor tackle technique.

Uruguay's set-piece dominance made the difference as Namibia's tighthead Coetzee was shown a yellow card for collapsing a scrum. Los Teros made the 14 men pay as Amaya acrobatically touched down one-handed in the corner.

The turnaround was complete when a lucky ricochet fell for scrum-half Santiago Arata, who weaved past two defenders to score a bonus point fourth try. Etcheverry converted both and Uruguay led 26-23.

Two cards in quick succession all but ended Namibia's hopes of earning that long sought-after first win. First Uanivi was penalised for a shoulder to the head and then Sethie was sent-off for a head-on-head collision.

Uruguay turned the screw and replacement fly-half Felipe Berchesi picked out right wing Bautista Basso with a chip kick to score in the corner. (AFP)