NOOSA Heads teenager Jordan Mercer has defended her long distance paddleboard title at Peru.

The 19-year-old finished the 22km race at Miraflores in a time of three hours, 23 seconds to narrowly beat South Africa's Anna Notten by 27 seconds.

Peruvian Rocio Larranaga was a further 28 minutes adrift in third place.

It was a remarkable turnaround from Mercer, who just three days earlier finished second in the final round of a gruelling Telstra Ironwoman Series at Noosa Heads.

Team Australia experienced a dominant day at the ISA World SUP and Paddleboard Championship, with Jamie Mitchell (men's stand-up paddleboard) and Brad Gaul (men's paddleboard long distance) also claiming victories.

Conditions were very challenging for the competitors.

"The athletes faced very challenging conditions with a dense fog, but they fought through and put on an amazing show," ISA President Fernando Aguerre said.

More in Friday's Sunshine Coast Daily.