Weir is still looking for his first Paralympic gold medal
Wheelchair racer Dave Weir could only win bronze in the T54 5000m on Thursday, leaving Britain still looking for their first gold on the track.
Weir has been struggling with a virus and after his second place in the 400m on Wednesday, he was out-sprinted with Thailand's Prawat Wahoram getting gold.
Weir said: "It's disappointing, but at least it's another medal in the bag."
The 29-year-old has still got a chance of winning his first Paralympic gold in the 800m, 1500m and marathon.
Weir had shown a return to form in the early session on Thursday, to grab the fastest qualifying time in the 800m heats in one minute 36.24 seconds.
Weir, silver and bronze medallist in Athens in 2004, revealed after the 5000m final his virus had still been affecting him.
"My nose was still blocked last night and I didn't get much sleep," he added. "Tomorrow I can have a lie-in, and hopefully I can pull through and get this bug out of my system."
The pace began slowly and although Weir was well-placed at the bell, he was pipped five metres from the line by Australian Kurt Fearnley, as Wahoram remained strong to win in 10 minutes 22.38s.
GB's Katrina Hart qualified for the 100m T37 final as one of the fastest losers, clocking a season's best of 14.94s, while Tracey Hinton was "chuffed" to have qualified for the T12 400m B final in 58.89s.
Tunisia's Mourad Idoudi won the men's discus, with Richard Schabel the best-placed Briton in 8th. Team-mates Stephen Miller and David Gale were unable to progress beyond the third round.
In the women's shot put F37/38, Britain's Beverley Jones threw a season's best 10.35m but had to settle for fifth, in a competition won by China's Na Mi.
Rebecca Chin was 10th with 10.47m, a PB for the 16-year-old Welsh student on her Games debut by nearly a metre.
Canada's Michelle Stilwell easily won the women's 200m T52, while in the 400m T54 first round, team-mate Chantal Petitclerc was in imperious form cruising through in a time of 52.50s.
Korea's Suk-Man Hong broke his own world record by over a second to win gold in the men's 400m T53, clocking 47.67s.