The Illawarra Hawks underlined their early standing as one of the NBL's prime championship contenders after starting their campaign with a convincing 81-71 victory over the Adelaide 36ers.

Bronze medal-winning Tokyo Olympian Duop Reath (18 points, nine rebounds) top-scored on his NBL debut, while Justinian Jessup (17 points, four steals) exploded during a decisive 26-15 third quarter which saw the Hawks assume total control.

Twin towers Cam Bairstow (15 points) and Isaac Humphries (13) led the charge for the Sixers, who self-sabotaged through relentlessly careless ball use and were flattered by the final margin.

"We were a little scrappy on the offensive end but you could see some really good patches for the future," Illawarra coach Brian Goorjian said.

"We've got much more shooting power on the perimeter than we had last year and we've got some athleticism.

"Defensively, to hold them to 71 on their home court was a good way to go in our first game."

Reath's sweet perimeter touch and ex-NBA swingman Antonius Cleveland's jaw-dropping athleticism - his steal and extraordinary reverse breakaway slam in the opening minutes silenced the Adelaide Entertainment Centre crowd - gave Illawarra an early 9-2 edge.

The Hawks went temporarily cold and the 36ers crashed the boards hard, riding a 12-0 spree to a 16-13 quarter-time lead.

Slick American Tyler Harvey dominated at both ends in the second term as Illawarra moved ahead 40-35 at halftime amid a slew of Adelaide turnovers.

It got worse for the 36ers in the third stanza, with more turnovers, an unsportsmanlike foul on struggling import Dusty Hannahs and a swag of buckets from Reath and Jessup extending the Hawks' advantage to 66-50 at three-quarter-time.

Journeyman guard Xavier Rathan-Mayes shook off his scoreless first half with a flurry of late buckets as the buffer blew out to 19 points, the 36ers ultimately left winless and their undefeated pre-season Blitz campaign when they claimed the Loggins-Bruton Cup now appearing an age ago.

"There were a few turnovers and the body language shifted," Adelaide coach CJ Bruton said when surmising how the game changed across the middle two quarters.

"Everyone got a little bogged down and second guessing.

"Things started unravelling and we gave up a lot of points in transition just off our turnovers.

"Across the board, it (turnovers) is the only statline that sticks out."