The visitors shot out a handy 10-0 advantage midway through the first half, before tries to Felix Patterson and Matt Hungerford either side of the break allowed QUT to hit the lead.
But late tries to Logans Ben Ah Sam and Andrew Tanholo allowed the Redbacks to steal the competition points, with a shattered Trouts outfit clinging to fourth spot after nine rounds.
The UQ Hounds leapt into second position courtesy of their 36-8 demolition of the Griffith Gold Coast Panthers at Nathan.
It was the Hounds running game that set up the six tries to two victory, allowing UQ to leapfrog the Panthers and secure a place in the finals.
And the USQ Ironbarks kept their semi-finals aspirations alive with a 20-0 victory over the Griffith Dragons.
Round 10 action sees the Trouts and Panthers battle it out for a top two finish at Aspley, the Dragons will look to finish the season on a high when they meet the Hounds and the Redbacks and Ironbarks face off in Toowoomba.
Round 9 results
USQ Ironbarks 20 def Griffith Dragons 0
Griffith Logan Redbacks 20 (Taniela Ilargana, Allan Alofipo, Ben Ah Sam, Andrew Tanhalo tries; Matt Oliphant 2 goals) def QUT Trouts 18 (Felix Patterson, Matt Hungerford, Kurt Dobbin tries; Richard Kay 3 goals)
UQ Hounds 36 (Brad Milne 2, Brendan Colley, Thomas Eledume, Ben Tassell, Carl Zammataro tries; Lachlan Pill 6 goals) def Griffith GC Panthers 8 (Nathan Land, Kurt Resch tries)