Michael Doughty hit sparkling form as the Rangers youngsters took Peterborough United apart on Saturday.
Doughty, who previously struck in the R's 3-1 win over Northampton Town, opened the scoring as he struck home off the underside of the cross-bar after some excellent movement on the edge of the area.
He grabbed his second from a set piece, when he curled the ball straight over the 'keepers head from a good angle.
He had the opportunity to net a hatrick when Raheem Sterling was brought down in the area, but it was Antonio German that stepped forward to dispatch the spot kick for Rangers third.
The goals appeared to be flying home in the first period and the unselfish Doughty grabbed his third when Aaron Waters lofty cross was tipped onto the bar by the stopper, only for Doughty to dive in and claim the match ball.
QPR were four goals to the good at the break and the result seemed a formality - not so for plucky Peterborough who grabbed two goals against the run of play after a couple of spurned opportunities from the R's.
Doughty was replaced by Irish youth international Frankie Sutherland, and it was a masterful change by Steve Gallen as Sutherland skipped past two players before firing home Rangers' fifth in style.
The R's recently learned that as a reward for their cup exploits against Brentford, they would play either Southampton or Hereford United in the Youth Alliance Cup.
This latest result puts the R's up to second, merely a point behind leaders Southend United with a game in hand.
It is the Bees again for QPR as they travel to face Brentford on Saturday, while Southend travel to Aldershot Town in a bid to extend their stay at the summit.
QPR: Niki-Lee Bulmer, Michael Harriman, Aaron Waters, Max Ehmer, Danny Bailey, Luke Olley, Michael Doughty, Elliott Cox, Andrew Perring, Antonio German, Raheem Sterling