Liam Millar scored twice as Birmingham won a crucial Sky Bet Championship clash 3-0 with QPR at St Andrew's.

In front of watching chairman Tom Wagner, Millar netted to swing the game Birmingham's way in the 27th minute and then doubled their advantage just after the break.

On both occasions he was assisted by Tomoki Iwata while Demarai Gray added the gloss in the first minute of stoppage time by hammering a pull-back by fellow substitute Luis Vazquez into the top corner as Birmingham confirmed a statement victory.

The visitors made a confident start and might have gone ahead from Paul Smyth's seventh-minute long throw.

The ball eluded Birmingham's backline and fell to Boy Kemper, but he was falling away on the stretch as he diverted it just wide from close range.

Birmingham had a huge shout for a penalty in the 18th minute after slicing through QPR down the right.

Kemper slid in to stop a pass reaching Bright Osayi-Samuel and succeeded in only scooping the ball back into the heart of the area.

As it bounced about amid a crowd of bodies, August Priske blasted a shot on the turn that struck the underside of Ronnie Edwards' upraised left arm as he tried to block.

Presumably the referee Thomas Kirk felt Edwards was in too close proximity for it to be avoidable.

There was joy, though, for the home side nine minutes later when they took the lead after a fast break from QPR's first corner of the match.

Jay Stansfield hassled Rayan Kolli out of possession not far from Birmingham's penalty area and as Kealey Adamson attempted to help, QPR got in a muddle.

Stansfield moved the ball onto Iwata and he slipped Millar clean through at halfway. The Canada international kept his composure to surge on and sidefoot a low shot past Pierce Charles at his near post, from the left of the area.

Three minutes before the break Kwame Poku fed Kolli down the right channel and he hit a powerful attempt at goal only for James Beadle, on his 50th appearance for Birmingham, to stand strong and beat it away.

Birmingham and doubled their advantage in the 49th minute, dispossessing QPR in midfield through Iwata and then teeing up Millar to finish.

After picking the pocket of Glen Kamara, Iwata advanced to the edge of the area and received a return pass from Patrick Roberts before rolling the ball into the path of Millar, coming in off the left. Millar swept the ball firmly first time past Charles from 10 yards to put clear daylight between the teams.

The R's refused to lay down however as they then stepped up efforts to try and retrieve the situation.

Beadle made an important, sprawling save to kept out a powerful sidefooter from Edwards from the angle of the area in the 63rd minute.

Millar came close to a hat-trick sooner after when Birmingham caused panic from a cross by substitute Carlos Vicente. The ball was flicked clear but only as far as Millar who thumped the ball fiercely on the volley but straight at a grateful Charles.

In the 69th minute the game exploded into controversy when Birmingham captain Christoph Klarer dribbled the ball out of defence and then overran it on his second touch. He slid in as Jimmy Dunne nicked it away and caught the R's skipper on the foot. Dunne writhed and rolled around in agony and once order was restored referee Kirk gave Klarer a talking-to and showed a yellow card.

As the clock ticked over to 90 minute plus one, the Blues capitalised as QPR pushed forward. Stansfield worked the ball to Vazquez on the right of the area and he laid it back for Gray to thump in from close range.