Mitch Norton's attempted game-winner was released a fraction of a second after the final buzzer and Cairns have hung on to beat Brisbane 102-101 in an epic finish to their NBL derby.
The Queensland rivalry ignited again in the second meeting between the sides since Bullets star Aron Baynes was hit with a five-game suspension for his altercation with Taipans players and coach Adam Forde in early October.
Both teams were coming off heavy losses and it was Cairns who started brightest in enemy territory at Nissan Arena on Sunday, racing away to a 35-17 advantage by quarter time.
The visitors led by as much as 22 points during the third term and maintained a double-figure buffer in a dominant display throughout the first three periods.
But the margin was slashed as Bullets veteran Sobey (24 points) caught fire early in the final term.
Baynes and Cairns star Tahjere McCall (25 points, nine assists) both fouled out in the dying stages and Sam Mennenga (18 points) missed a three that would have rubber-stamped the visitors' win with a few seconds remaining.
Brisbane rebounded and Sobey drove hard towards the basket before dishing out to a wide-open Norton, who sunk his long-range shot after the buzzer sounded.
It was too late for the Bullets, who have now lost six consecutive home games to their rivals over a three-year period.
"Those things happen ... it was the right play," Norton said.
"Sobes attracted a lot of attention, as he does, and made the right read.
"Split second and the game's ours, but there's a lot of things that happened before that that led to the outcome of the game.
"The good thing is the fight and the character of this squad to come back in the second half, and that's what I'm proud of.
"At the same time, we lost the basketball game. There's areas we can focus on and improve."
Bullets coach Justin Schueller was left ruing his team's slow start.
"We just need the hoop gods to give us a little bit more time on that one and we feel totally different about this," Schueller said.
"But the start of the game and start of the third quarter is just not acceptable for this club."
McCall scored nine of his points in the final quarter in a vital contribution for the Taipans as Sobey dragged his side back into the contest with 14 points for the term.
Bul Kuol (19 points) and Patrick Miller (17) were also influential as all five of Cairns' starters scored in double figures.
"It's important to get these wins knowing that it's not just a win for us but it's a loss for a team that we're competing against," Taipans coach Adam Forde said.
"That's where I felt we let ourselves down in New Zealand (last week) but it was a great job by the boys to bounce back for this one.
"Now we need to roll in and make it two in a row against South East (Melbourne)."
Josh Bannan registered 15 points and 10 rebounds on his return from a stint on the sidelines recovering from concussion for Brisbane, while Norton and Isaac White added 13 points each.
The Bullets' hulking 220cm centre Rocco Zikarsky gave a taste of his defensive capabilities with four huge blocks.
Cairns (7-9) have now gone six games in December without posting consecutive wins or losses, while Brisbane (also 7-9) have fallen out of the top six.
Unusually, the away team has won each of the three Queensland derby encounters so far this season, with one left to play in Cairns on January 21.
