Earlier, eight of the 16 surfers who have flown in for the event competed in triple overhead waves that weren't for the faint-hearted.
Allport, Jesse Polock, Blake Thornton, James Adams, Russell Bierke, Evan Faulks, Richie Vaculik and 16-year-old Riley Laing all took turns riding waves that were as nasty as any you'll ever see in an organised surf contest.
There were some unbelievable barrels, some even crazier wipe-outs and at the end of the day Allport (two wave combined score of 15.25) stood atop the leaderboard ahead of Bierk (15.05), Faulks (14.15) and Adams (14.10).
Aussie world surfing champion Mark Occhilupo said risk facilitator Paul Chivers had no choice but to put the event on hold around 2pm as a low tide made performing a rescue extremely difficult for water safety crews on jetskis.
"It got way too dangerous out there, didn't it," Occhilupo said. "Everyone was getting sucked over the falls and so close to going over the rocks. It was so lucky no one got seriously hurt today ... Tomorrow it could be a little smaller, but way more manageable."
The coast was closed to the public for safety reasons but anyone who tuned into a live stream of the contest got their money's worth.
The brainchild of Aussie big wave surfing legend Mark Mathews, Cape Fear pits surfers against each other in man-on-man heats at a wave Mathews describes as "pound for pound the heaviest and most dangerous wave in the world".
The event is running at Cape Solander - on the edge of Botany Bay in southern Sydney - from June 6-7.
Koby Abberton, Dean Morrison, Jai Abberton, Kirk Flintoff, Andrew Mooney, Perth Standlick, Ryan Hipwood and Laurie Towner are scheduled to compete tomorrow.
"There's a lot of floggings happening," said Towner, when the decision was made to go on standby. "I guess it's a good call but I'd still like to surf."