LOOKING at him it is hard to imagine that surfing great Mark Occhilupo is 40.

For former world champion celebrates his birthday today though the celebrations started yesterday with a special function thrown by his long-time sponsor Billabong at their Burleigh headquarters.

Occhilupo won't have long to celebrate his 40th on the Gold Coast as he will head to Mexico on Monday for the fifth event on the world championship tour, still confident of upstaging his younger rivals.

"I still feel 21," said Occhilupo, the last Australia man to win a world surfing title. "I'm not looking to be competing when I'm 50 but if I am still on tour at 45, I will be."

The goofy footer is currently ranked No.20 on the overall standings, with his best result a third place this year at Bells Beach.

He'll be looking to jump further up the rankings with good results at his favourites events at Jeffreys Bay, South Africa and Mundaka in the Basque region of Spain yet to come.

Occhilupo will return from Mexico in time for the finals of the Billabong Occy Grom Comp for surfers aged 16 and under.

More than 200 of the nation's best juniors will descend on the Gold Coast in July to take part in the five-day competition at D'bah.