Sophie McCulloch has nabbed the final qualifying spot for next year's top tour with an upset victory at the final World Surf League qualification event in Hawaii.

The Australian took the fifth spot on offer - but only just, after local favourite and defending Haleiwa Challenger champion Bettylou Sakura Johnson's brilliant wave almost trumped her.

Needing a win to qualify, McCulloch (15 points) had taken control of the heat but could only watch when Sakura Johnson's (14.23) 9.23-point effort fell short of the perfect 10 she needed to snatch victory.

She will join the top tour, which begins in January's Billabong Pipeline on Hawaii's North Shore, with compatriots and fellow qualifiers Molly Picklum and Macy Callaghan who finished second and third in the qualifying series.

"It means so much to me, and I actually had a lot of self-doubt heading into this event," said McCulloch, admitting she was not sure of the qualification scenario before surfing the final.

"Someone told me it's not over, so I didn't know exactly what needed to happen and just knew I needed to give it my all.

"It added some nerves, but I'm really proud of my ability to regroup and just have the same intention."

Fellow Australian and men's qualifier Liam O'Brien will also get his shot at the Championship Tour after injury meant he was unable to compete this year.

Newcastle's Ryan Callinan will also return to the Championship Tour, after finishing second in the qualifying series.