The midfielder started alongside Pelly-Ruddock Mpanzu and Louie Watson, and opened the scoring just after the half-hour mark, before QPR hit back after the break.
After Avan Jones found the bottom corner with a well-hit effort, the away side struck back through Shannon Brown with seven minutes to play.
Not deterred, the young Hatters found a winner through Tobias Braney in front of 488 fans on a chilly September evening.
It was the youthful away side made a strong start to the game and could have taken the lead on two occasions in the opening 10 minutes.
After Josh Allen was dispossessed, QPR attacked with pace as Kieran Petrie found Micah Anthony with acres to attack on the right, and his curling effort was just wide of the post.
The aforementioned Petrie then went close himself after getting past Josh Williams but not Casey Pettit, who made an important block to stop his goal-bound effort.
After surviving the initial attacks from the away side, Adrian Forbes’ side started to assert their dominance on the game.
Berry – starting after sporadic first-team appearances so far this season – came close with a moment of magic as he saw Harry Halwax off his line and tried his luck from 25 yards, but his effort was just over the bar.
Allen then struck the post twice in as many minutes, first with a superb curling effort that bounced off the inside of the post, followed by a right-footed effort with clipped the outside and went behind.
But Town’s luck in front of goal would quickly change as Watson delivered an inch-perfect corner and Berry headed powerfully past Halwax.
The midfielder was replaced at half-time by Zack Nelson and QPR quickly found a route back into the game through Teddy Lawrence, who beat Jameson Horlick with a low shot inside the area.
Pelly-Ruddock Mpanzu was replaced shortly after the hour mark before the young Hatters went ahead once more with just over 20 minutes to play.
It was a strike worthy of winning any game too, as Jones struck low and fiercely past Halwax on the angle into the far corner.
The away side would have other ideas, however. Following a scramble in the box, the ball fell kindly to substitute Shannon Brown on the edge of the box and he picked out the top corner, leaving Horlick without a chance.
But there was one final twist in tale as Zack Nelson's shot cannoned off the post and Braney was on hand to smash the ball in from two yards, maintaining the Development Squad's unbeaten start to the season.
Development Squad: Horlick; Jones, Pettit (C), Tompkins, Williams; Mpanzu (Newton 63'), Watson (Idiakhoa 72'), Lawless, Berry (Nelson 45'); Allen, Braney.
Subs not used: Bentley, Luker, Pinnington, Matthews-Lewis, Odell-Bature.
Goals: Berry (32'), Jones (69'), Braney (88')
QPR U21s: Halwax; Siqueira, Leahy, Cotter (Sackey 55’), Rossi, Pitbaldo (C), Petrie, Smith, Lawrence (Brown 74'), Dougui (Talla 51’), Anthony (Hamid 70').
Subs not used: Salamon.
Goals: Lawrence (50'), Brown (83')
