The Tasmania JackJumpers have set a team-high total against Adelaide in a 23-point win to leave the 36ers' brave NBL Finals bid on "life support".
Sunday's 109-86 victory consolidated third-place and top seeding for Tasmania in the league's play-in tournament, although second place is still a mathematical chance after Perth (16-9) lost to New Zealand Breakers later on Sunday.
And it left the resurgent 36ers needing a miracle in the final two rounds to join them, two days after a win over Cairns left the Taipans in a similar predicament.
Trey Kell (29 points, 10 rebounds) did his best for the 36ers and Dejan Vasiljevic (21 points) tried to limit the damage.
But a costly passage in the second quarter, when the lead blew out from 10 to 19 in two error-riddled minutes, all but put a victory out of the visitors' reach before halftime.
Tasmania shot at 60 per cent, comfortably won the rebound count and played unselfishly to notch the club's highest score with their final bucket of the afternoon.
Milton Doyle won player-of-the-game honours with 17 points and 10 rebounds, while Jack McVeigh (26 points and eight rebounds) was everywhere and five others scored at least nine points.
The 36ers were 5-9 when coach CJ Bruton was axed and replaced by club great Ninnis, who had the squad believing they could surge into the finals when they beat two-time defending champions Sydney on Friday.
But now, after falling to 11-15 and second-last on the ladder, Adelaide need to win both of their final games, boost a relatively poor percentage and hope Brisbane, the Breakers and Cairns crumble.
The Breakers (11-13) have other ideas though, with their Sunday upset moving them level with the 36ers on wins but with two games in hand.
"They play with a determination that if you don't match you're going to have results like that," Ninnis said.
"We're now on life support. It's devastating; we set ourselves up nicely ... and it all came unstuck for us with so much to play for."
The JackJumpers (14-12) are two wins clear of Illawarra, Sydney and Brisbane in a stacked middle section of the ladder, although the Hawks have two games in hand.
Tasmania made the final in their maiden campaign, then lost in the semi-finals last year.
Coach Scott Roth began his post-game press conference with a strong endorsement of Scott Ninnis for the full-time job at Adelaide next season and then fought back tears when told the 36ers' interim coach had taken plenty from the JackJumpers' NBL approach.
"I'm proud of what we've done here ... for other teams to emulate anything we're doing is a credit, I can't thank him enough for that comment," he said.
Roth said a faster tempo and the presence of Will Magnay, who played after sustaining a knock to the ribs on Friday, had contributed to the JackJumpers becoming a higher-scoring team.
"The biggest thing is unselfishness of the group to keep the ball moving," he said.
"We don't tell anyone to turn down shots ... it's guys doing the right thing."