The first Whittlesey Triathlon took place at the Manor Leisure Centre with about 130 competitors taking part.
The event was run at the leisure centre with children aged eight to 16 and adults tackling the swim, cycle and run.
The event, run by Triathlon England, saw one young girl raise £1,700 for charity and a grandfather and grandson compete.
“It was a real success, it went beyond our expectations,” said Whittlesey Triathlon Club secretary Jon Chamberlain.
“We will definitely run another event next year.”
The winner in the main category was Jodie Elliott, with Ryan Howe registering the fastest time for a male.
In the youths’ section, James and George Bowen took the top two places.
Between 300 and 400 spectators watched the event.
The triathlon aimed to give those who had never taken part in one before an introduction to the sport.
The club is seeking new members to join and their Facebook page is called Wi-Tri.