Kyjuon Marsh-Brown volleyed home ten minutes from time to extend Brentford's unbeaten run to four Under-18 Professional Development League Two South games.
The winger met Jeremiah Kamanzi's cutback to secure a share of the points against Bristol City at Jersey Road.
Matt Mattis had given City a fourth minute lead which it looked like they would hold on to until Marsh-Brown's intervention.
Jon De Souza made three changes from last Saturday's 2-1 win over Cardiff City with Seth Owens, Courtney Senior and Julius Fenn-Evans coming in for Audrius Laucys, Makhosini Khanye and Kingsley Eshun.
From the off it was clear what City's game-plan was as they looked for the pace of Mattis and Joe Morrell in behind the high Brentford backline.
It took less than four minutes for that game-plan to bear fruit as Morrell twisted and turned past Chris Mepham and his cut-back was slammed home from eight yards by Mattis.
The game was a marked contrast of styles in the early stages as Brentford's patient passing build-up was the polar opposite to City's direct style.
Senior could have marked his recall with a goal but he fired straight at Jojo Wallacott from 10 yards and Fenn-Evans' curling effort was easy for the City stopper.
Mattis and Morrell combined again for the visitors just before the quarter hour but this time Morrell's shot flew just over.
Zain Westbrooke shot over from the edge of the box before only a terrific double intervention from Ben Last prevent Jeremiah Kamanzi levelling matters from close range midway through the half.
Mattis fired over and four minutes later Brentford thought they were level only for the linesman's flag to deny Kamanzi and he slotted home after a clever free-kick routine.
Bohui's weak shot was easy for Wallacott as Jon De Souza's side continued to have the better chances.
Connor Evans shot weakly at Nik Tzanev but it was The Bees who had the final shot of the half as Senior fired over from the right hand side of the penalty area.
Playing against the wind in the second-half somewhat negated City's direct style and aside from a Bohui shot that was easy for Wallacott and a Mattis effort that was superbly blocked by Owens neither goal looked in any danger in the opening 20 minutes of the half.
As the half wore on it was The Bees who took control of the game and had City penned back in their half for large spells.
Audrius Laucys headed straight at Wallacott before Brentford got the equaliser they deserved with ten minutes remaining as Senior and Kamanzi combined on the right-hand side of the box and Marsh-Brown arrived late to smash home Kamanzi's low cross.
City were desperately hanging on in the closing stages as The Bees piled on the pressure but try as they might Brentford couldn't find a way through.
The closest Jon De Souza's side came to a late winner saw Laucys unable to sort his feet out and bundle the ball wide after Wallacott had made a good low save from Senior's close range effort.
: Nik Tzanev; Chris Mepham (sub Kyjuon Marsh-Brown 56 mins), Gradi Milenge, Seth Owens, Tom Field; Jeremiah Kamanzi, Zain Westbrooke, Julius Fenn-Evans (sub Audrius Laucys 66 mins), Courtney Senior; Joshua Bohui (sub Makhosini Khanye 86 mins), Bradley Clayton
: Jordan Carey, Tony Guppy
: Kyjuon Marsh-Brown 79
: Jojo Wallacott; Jack Alexander, Zak Vyner, Tom Fry, Ben Withey; Jake Andrews, Ben Last, Joe McNulty, Joe Morrell (sub George Dowling 76 mins); Connor Evans (sub James Difford 74 mins), Matt Mattis
: George Kellow, Will Henry, Matt Long
: Matt Mattis 4