LONDON (Reuters) - Britain's Ed Clancy destroyed the opposition when he clocked the fastest time in the 250-metre flying to take the early lead in the Olympic omnium at the cycling velodrome on Saturday.

A day after winning the Olympic team pursuit with his British team mates in world-record time, Clancy rode his lap in 12.556 seconds, more than half a second faster than second-placed Shane Archbold of New Zealand.

Australian Glenn O'Shea was third.

The omnium is a test of all-round skills over two days in six disciplines: a flying lap, 30-km points race (20 km for women), elimination race, 4-km individual pursuit (3km), 15-km scratch race (10km) and one-kilometer (500m) time trial.

Points are added up depending on placing in each event and the rider with the lowest points score wins.

(Reporting by Julien Pretot; Editing by Clare Fallon)