Welsh cycling superstar Mark Colbourne smashed the world record and won a gold medal in a day of high drama and emotion in the velodrome.

Colbourne, 42, who fought his way into the sporting elite after breaking his back in a paragliding accident, became the toast of Paralympic cycling with a devastatingly fast ride in the 3km pursuit.

It came a day after the Tredegar cyclist marked his Paralympic debut with a silver medal.

He dedicated his gold to his late father Cecil, who died earlier this year, and said of realising his dream: "I keep pinching myself."

Minutes before his triumph, the velodrome crowd had been booing a decision to deny British cycling phenomenon Jody Cundy the right to ride for a gold medal in the C4/C5 one-kilometre time-trial.

Cundy's back wheel spun and slipped at the start and his appeal for a re-start was denied - leaving him to make an expletive-laden emotional outburst as the fans jeered in disbelief.

In the same event, war hero Jon-Allan Butterworth won a silver medal.

Butterworth, who lost an arm in a rocket attack on Basra air station in Iraq in 2007, said after his thrilling ride: "It's amazing. The crowd really got behind me and it was a great feeling."

The velodrome's triumphs and disasters came on another day of excitement, inspiration and deep emotion at the Games.

Martine Wright, who lost both her legs after being horrifically injured in the 7/7 bombings, fulfilled her dream of representing her country at the Paralympics as she pulled on the number seven shirt in recognition of the day that changed her life and took her place in Britain's sitting volleyball team.