The Western Force have ended Queensland's Super Rugby finals' hopes with a 40-26 victory on Friday night at Suncorp Stadium.

The Reds needed a win to stay alive in the race for the Australian conference, but the Force overran them with 17 unanswered points in the second half.

A late yellow card to winger Eto Nabuli - who made needless high contact with Force five-eighth Peter Grant, as he collected a high ball with less than 15 minutes to go - cruelled any chance of a Queensland comeback.

Test hooker Tatafu Polota-Nau came off the bench to seal it for the Force with his 70th-minute try, while Grant's fourth penalty of the night was the final nail in the coffin.

Grant didn't miss a kick all night and contributed 18 points off his own boot, with the Force leapfrogging the Reds in the Australian conference.

Nabuli's sin-binning came shortly after Marcel Brache scored to put the Force back in front 30-26.

It was the second yellow card of the night for the Reds, taking their season tally to 12 - more than any other team in Super Rugby.

Halfback Nick Frisby was shown the first yellow in the 44th minute and conceded a penalty try for kicking the ball out of Michael Ruru's hands as he leapt over a ruck to plant down.

It will be a sore point for Reds coach Nick Stiles, who had brought in referees to training during the week in an attempt to stamp out the root causes of their costly ill-discipline.

Wallabies skipper Stephen Moore tried to drag the Reds back into it with a second-half double but he could not inspire his teammates in front of just 12,040 fans.

Frisby endured a torrid night, but was briefly a hero for the Reds as he helped set up Lukhan Tui for a try just two minutes after halftime with a surging counter-attacking run.

The Reds started brightly enough and led 5-0 when Duncan Paia'aua was set up by a Quade Cooper dummy and crossed for the opening try just five minutes in.

But continued turnovers and poor field kicking allowed the Force to turn the rest of the first half into a grind, with two penalties and Ross Haylett-Petty's debut try giving them an 11-5 lead at the break.

Force coach Dave Wessels was delighted with the turnaround from his side after they were demolished last week at home by the Highlanders.

"There was no doubt our intensity won us that game," he said. "I've had a lot of special wins with the Force but that ranks right up there because of the context of where we've come from."

Stiles accused the Reds of taking "soft options" and said their yellow cards were unacceptable.

"I'm filthy," Stiles said. "We can't sustain 80 minutes of football. We're happy to do things in spurts and patches but that doesn't win you football games."