However, Alan Thompson's side could, and arguably should, have had all three points from this entertaining encounter after Will Packwood's second-half header had levelled scores following Michael Doughty's 29th minute opener.
Thompson, taking charge of his first competitive game as senior professional development coach, was able to name no less than eight first-teamers in his starting XI with recent recruit Denny Johnstone, on the bench for the seniors against Brighton & Hove Albion on Saturday
, leading the line for the hosts.
Blues were much the better side throughout this U21 Professional Development League Two match-up but struggled to find their way past a resolute QPR defence.
The hosts were forced into a change after just 25 minutes with Viv Solomon-Otabor replacing Andy Shinnie, whose back strain looks set to rule him out Tuesday night's Sky Bet Championship fixture at home to Ipswich Town
Against the run of play, QPR took the lead. Matt Phillips cross from the right was parried away by Connal Trueman but only into the path of visiting captain Doughty who thumped home from 12 yards.
Blues continued to rally to ensure that play stayed in the QPR half. In the 36th minute, the impressive Reece Brown set Johnstone on his way and he fired a low shot narrowly wide of the left post.
Joe Lumley, in the QPR goal, was forced into action twice before the interval. Once to comfortably smother Solomon-Otabor's 20-yard effort but getting down to palm away Callum Reilly's stinging low drive from distance.
Blues continued in the same vein after the break; Mitch Hancox's persistence in the away side's box forced Lumley into a save before Olly Lee had the ball in the net only for his effort to be chalked off for an offside.
Thompson's troops maintained their pressure and Neal Eardley, skippering the side, had the woodwork shaking with a thumping volley from 30 yards that rattled the underside of the crossbar.
Eventually, the pressure paid off in the 68th minute. Lee's free-kick from the right picked out the head of Packwood at the far post and the American made no mistake.
Hancox wasted a glorious chance to win the match in injury time. Racing on to substitute Liam Truslove's throughball, the left-back only had Lumley to beat but the QPR goalkeeper read his attempt to knock the ball under his onrushing frame.
Trueman, Eardley (C), Hancox, Reilly, Packwood, Bell, Brown (Truslove 62), Lee, Johnstone (McGee 62), Shinnie (Solomon-Otabor 29), Nasseri.
Subs not used: Fry, Adams.
Lumley, Furlong, Kpehawa, Gibbons (Mitchell 76), Donaldson, Sendles-White, Phillips (Sutherland 63), Harriman, Andrade (Grego Cox 84), Doughty (C), Comley.
Subs not used: Lennox, Wise.