Mark Colbourne experienced ecstasy and Jody Cundy despair on a dramatic second day of Paralympic competition at the London 2012 velodrome.
Colbourne claimed Paralympic gold for the first time with victory in the men's C1 three-kilometres individual pursuit in a world record time, on a day which saw Britain claim one gold, three silvers and a bronze.
Cundy, though, experienced only anger and tears after he was denied a restart in the C4/C5 one-kilometre time-trial, an event in which he had not been beaten in six years.
There was a happier conclusion to the day for Colbourne, who set a second world record in the space of a few hours in winning gold in three minutes 53.881 seconds.
China's Li Zhang Yu, who won C1-2-3 one-kilometre time-trial gold ahead of the 42-year-old Welshman on day one, was second.
"It's a dream come true for me," said Colbourne, who broke his back in a paragliding accident in 2009. "I only had 18 months (to prepare). We had to raise the bar, increase the training and push me to my limits. Today was the result of all of that."
The C4/5 one-kilometre time-trial was won by Alfonso Cabello in a C5 world record of 1:05.947, with world champion Jon-Allan Butterworth, who lost his left arm while serving in Iraq with the RAF in 2007, taking silver in 1:05.985, 0.038 behind the Spaniard. Bronze went to China's Ji Xiaofei.
Butterworth had been concentrating on the C5 4km individual pursuit, which takes place on Saturday, expecting Cundy to win the kilo. The 26-year-old from Sutton Coldfield said: "I'm pleased with the silver. I'm confident tomorrow, it's a new day so let's hopefully go for gold.
"The kilo historically I'm very good at but I've been concentrating on the pursuit as I thought Jody would be very hard to beat. Unfortunately that did not happen, I'm guessing he probably would have won that the way he's been going in training."
Cundy believed the start gate had failed to open sufficiently for his ride, but officials deemed rider error was to blame and the 33-year-old was denied a restart.