Brentford endured a day to forget at London Road as an inspired Peterborough United side made use of playing almost the entire match with an extra man to inflict a heavy defeat.
Aaron McLean's first half hat trick put the home side on their way and goals from Chris Whelpdale, George Boyd, Craig Mackail-Smith and Rene Howe competed a dismal afternoon for the visitors.
The Bees could not have had a worse start, finding themselves a goal and a man down inside the first three minutes.
Boyd's pass found Mackail-Smith and he escaped the attentions of the Brentford defence to get a run on goal, Simon Brown slipped as he advanced and then brought the Peterborough forward down, when McLean failed to convert the re-bound referee Paul Armstrong had little choice but to award a penalty.
The Berkshire official dismissed Brown for denying a goal scoring opportunity and The Bees were forced to introduce Clark Masters, in place to Charlie Ide, to play in goal.
And his first touch was to pick the ball out of the net as McLean dispatched the penalty with aplomb.
The early goal and sending off only served to boost the hosts and they pressed forward, Mackail-Smith cracked a shot wide, Whelpdale headed over and McLean nodded wide.
Peterborough did get their second goal just before the quarter hour when a nice interchange of passes led to Boyd feeding Jamie Day on the left, his cross was met by McLean, who met the ball with a scissor volley which bounced over Masters and in to the corner.
The hosts were beginning to pepper The Bees goal, Masters saved well from Charlie Lee, Boyd fired wide and Micah Hyde shot well over.
McLean was the main danger and Masters denied him with a fine low save after a sharp turn but the Peterborough striker missed a great opportunity for a third goal just before the half hour.
A penalty was awarded against Glenn Poole when he was adjudged to have deliberately handballed a Claude Gnakpa cross but McLean hit the crossbar with his effort from 12 yards.
Masters denied him again with a fine tackle 25 yards from goal when he looked set to race clear and Lee fired across the face of goal before Craig Pead blocked another McLean shot.
But the Posh striker did claim his hat trick minutes before half time rounding off a fine move involving Boyd and Mackail-Smith with a lashed effort into the top corner.
Masters saved brilliantly from Boyd and Lee chipped an effort just over before Whelpdale added a fourth, converting from close range after Lee drilled the ball across.
Boyd scored the fifth soon after the break, firing powerfully in from a tight angle, and Mackail-Smith capitalised on a deflected pass from Day to race clear and slot home the sixth.
Masters produced another brilliant save when Lee's effort looked set for the top corner and denied substitute Howe from eight yards as the visitors failed to clear.
Brentford did have some efforts of their own, Poole lashed a shot in from 30 yards that flew narrowly wide and Lee Thorpe fired over from a corner.
But at the other end Whelpdale fired over and Mackail-Smith had an overhead effort saved before Howe added the seventh when substitute Dean Keates picked him out with an intelligent pass.
Howe headed a Boyd cross against the crossbar minutes later and Whelpdale was denied his second goal of the afternoon when Mr Armstrong adjudged that Masters had been fouled before the wide man put the re-bound in.
Keates shot into the side netting and Whelpdale lashed over before Poole fired over at the other end and John Mackie looped a header onto the top of the net.
Howe came close to a goal before the end but Masters saved well again from his low shot before Mr Armstrong brought proceedings to a close.
Peterborough United: Tyler; Gnakpa, Morgan, Westwood, Day (sub Hughes 63 mins); Whelpdale, Lee (sub Keates 70 mins), Hyde, Boyd; McLean (sub Howe 63 mins), Mackail-Smith
Subs (not used): Low, Jalal, Hughes
Bookings: Lee (33 mins), Whelpdale (68 mins)
Brentford: Brown; O'Connor, Heywood, Mackie, Charles; Ide (sub Masters 2 mins), Pead (sub Shakes 57 mins), Poole, Dickson; Thorpe (sub Connell 81 mins), Sinclair
Subs (not used): Smith, Montague
Sent Off: Brown (1 min)
Written by Chris Wickham