Poor conditions at Lower Trestles ends first day early

The opening day of the World Surf League event at Lower Trestles has come to an early end due to declining weather conditions.

Only two men's heats were completed on Friday (Saturday AEST) after prevailing winds deteriorated the four-to-six-foot waves.

Championship Tour (CT) rookie Luke Thompson (10.16) won the all-South African battle against Matthew McGillivray (9.34) and Hawaiian Eli Hanneman (9.73) just pipped Hayden Rodgers (9.67) of the US.

"For Matt and I, this our fourth heat together, which is pretty brutal. It feels good it's done, but it's unfortunate to deal with the only other South African on Tour in a first heat."

Stop No.9 on tour in California will resume with an all-Australian battle between Joel Vaughan and Oscar Berry.

Conditions permitting, six other Aussie men - world No.7 Ethan Ewing, George Pittar (nine), Liam O'Brien (11), Jack Robinson (12), Morgan Cibilic (16) and Callum Robson (18) - will also open their campaigns in coming days, as will defending champion, Brazil's Yago Dora.

Reigning world champion Molly Picklum will hope to better her runners-up finish from 12 months ago and is one of four Australian women competing in San Clemente, along with 2014 winner at Trestles and eight-time world champ Steph Gilmore, 2016 winner Tyler Wright and Sally Fitzgibbons.

The top 22 men and 14 women will be decided after Lower Trestles for the post-season events in Peniche, Portugal and Cloud 9, Philippines before the CT concludes and world champions are decided at December's Pipe Masters in Oahu, Hawaii.