A three-goal salvo late In the first half from Chesterfield consigned Brentford to their second league defeat of the season at Saltergate.
Two goals from Caleb Folan and another from Paul Shaw inside eight minutes late in the first period gave The Spireites a lead they were never to relinquish.
It was Folan who was first to get his name on the score sheet with half an hour gone when he latched onto a long clearance from Aaron Downes, skipped past Matt Heywood and finished superbly from twelve yards.
The home side's lead doubled six minutes later when The Bees failed to clear a corner, the ball dropped to Derek Niven who lashed in a shot, Stuart Nelson threw his body in the way of the first shot but was powerless to prevent Shaw smashing home the re-bound.
And Nelson had absolutely no chance with Chesterfield's third three minutes later.
Kevan Hurst, who had a superb first half on the left wing, flew past Karleigh Osborne and stood a cross up to the far post, Paul Hall knocked it back across and Folan turned it home.
The three-goal blast killed the game as a contest and the home side could have been ahead even before that.
Shaw fell over under pressure from Heywood when in a good position early on, headed wide when well placed from a Hurst cross and the former Rotherham United striker also blasted wide from 12 yards.
The Bees best early chance fell to Calum Willock who rose to meet a Paul Brooker free kick but he headed over from eight yards out and once Chesterfield grabbed the game by the scruff of the neck there wasn't much of a way back.
The Bees did get a lifeline in first half stoppage time through Adam Griffiths' first goal for the club.
Willock almost created a goal for Brooker with a fine reverse pass but Spireites stopper Barry Roche turned away his shot but from the resulting corner Chesterfield failed to clear, Thomas Pinault lashed in a shot and Griffiths turned home from six yards out.
The home side thought they had added a fourth early in the second half when substitute Colin Larkin turned home from close range but he was given offside.
The Bees tried to force an opening and find a way back into the game, Willock headed wide and Simon Cox had a shot saved but the danger still came at the other end.
Downes headed wide from a Hall free kick and Allison also missed when well placed but Chesterfield needed to do little more than play out time and they did so comfortably to take all three points.
Chesterfield: Roche; Bailey, Downes, Hazell, Picken; Hall, Niven, Allott, Hurst; Shaw (sub Larkin h/t (sub Kovacs 88 mins)), Folan (sub Allison 50 mins)
Subs (not used): Jordan, Lowry
Brentford: Nelson; Osborne, Heywood, Griffiths, Tillen; Brooker (sub Peters 59 mins), Cox, Pinault (sub Mousinho 88 mins), Tomlin (sub Charles 80 mins); Kuffour, Willock
Subs (not used): Masters, Carder-Andrews
Bookings: Griffiths (82 mins) (second of season)
Attendance: 3,877 (325 Bees fans)
Written by Chris Wickham