Britain's John Garcia-Thompson remained upbeat after he and team-mate Steve Grotowski slipped to their second defeat in as many games at Horse Guards Parade, insisting they had been beaten by "the best team in the world".
Brazil's Ricardo Santos and Pedro Cunha simply had too much power and experience for the British pair, winning in straight sets, 21-17 21-12, to advance to the knockout stage.
Even though Ricardo and Cunha are officially ranked as the second-best team from Brazil, and seeded only seventh in the world coming into the Olympics, they are among the favourites for a medal.
"We lost to the best team in the world," said 33-year-old Garcia-Thompson. "Ricardo could be the best player of the tournament. There were some good moments [in the match] absolutely but we needed a couple more. They're a very good team and we had to play very well to beat them.
"When we did play well we scored points, but we needed to do it a few more times. We were keeping at their level in the first set, then they brought some good digs and some aces early in the second set and we just couldn't keep the level."
The British pair began the contest encouragingly, surging into a 3-1 lead before the Brazilians rattled off six straight points to turn the tide, and despite a home side fightback, Brazil maintained their advantage to close out the first set.
Brazil took the match by the scruff of the neck in the second racing away to 12-5, before an ace by Ricardo brought up 10 match points, as the South Americans took victory soon enough.
Despite the defeat Grotowski hailed the support at Horse Guards Parade, saying: "The crowd were really good - 100 times better than anywhere - it's amazing how positive they are all the time. If they do this when we lose we'd just like to see what they do when we win a match - they'd go mental."
After their winless start to the three-match preliminary phase, Britain must triumph in their final Pool F match against Norway on Wednesday and hope other results go in their favour if they are to have any chance of continuing in the competition.
And Garcia-Thompson added: "We need to create the mentality that we had in the first set [today]. We need to be consistent - we cannot make three, four mistakes in a row. If we can be consistent then I think we have a chance."