Kelly Slater has endorsed Jack Robinson as the World Surf League's "most clutch guy" after the Australian locked in a third-straight Finals appearance.

Red-hot Robinson secured his berth in the title-deciding finals day after winning a heart-stopping round-of-16 clash in the Fiji Pro on Friday.

Compatriot Molly Picklum then did similar to earn a second-straight appearance at the top-five, one-day, winner-take-all showdown at Lower Trestles in California next month.

Ethan Ewing, ranked fifth entering the event, also remains on track thanks to a stress-free victory in a must-win heat against compatriot Ryan Callinan to reach the final eight.

West Australian world No.3 Robinson only needed to progress to the quarter-finals to punch his ticket but the Olympic silver medallist had to scrap his way to a win over Sydney surfer Connor O'Leary, who now competes under the Japan flag.

Robinson trailed O'Leary until the final few minutes at Cloudbreak when his rival blew a golden chance to extend his lead, falling on one of the waves of the heat.

He made the most of it, Robinson scoring a 5.67 for a combined total of 12.34 to topple O'Leary's total of 11.50.

"It feels so good, so happy to be there," Robinson said of sealing his berth.

"The last three years I've been in the finals; it's special, it's right where I'm meant to be ... (I'm) making it happen."

Eleven-time world champion Slater, given a wildcard for Fiji in what was likely his tour farewell, said Robinson was ready to go all the way this year.

"Jack seems like he can't put a foot wrong in critical situations," the American said.

"In these high pressure heats, where sometimes he's the underdog ... so much is on the line and he just nails it.

"He's been the most clutch guy in the past couple of years in those heats."

Robinson can do Ewing a favour by beating Yago Dora in their quarter-final clash when competition likely resumes on Saturday, the Brazilian looming as the major threat in the finals race after his surging countryman Gabriel Medina was beaten and knocked from contention on Friday.

Earlier Picklum (13.73), fresh off an Olympic campaign in Tahiti like Ewing and Robinson, locked in consecutive end-of-season finals after leaving French rival Johanne Defay (13.17) high and dry in their quarter-final.

The Australian found a long barrel and made a tough exit as the wave broke on her head for a 6.73-point wave that turned their heat.

Defay then chased a reply as the tide went out and was stranded in ankle-deep water on Fiji's shallow reef, wasting crucial minutes attempting to return to the line-up.

Picklum will meet on-song wildcard Erin Brooks for a spot in the final, the Canadian rookie already boasting the scalps of Gabriela Bryan and world No.1 Caitlin Simmers in her CT debut.

Tyler Wright (11.47 points), despite being out of final-five contention, was in a giant-killing mood as she took out reigning WSL and Olympic champion Caroline Marks (9.94) to reach the final four.