Ten-man Peterborough saw their 100% home record wrecked by Notts County after a 3-2 defeat at London Road.
County's first away win of the campaign was followed by a mass touchline brawl involving players, substitutes and officials from both clubs immediately after the final whistle.
The game erupted into life with four goals in an all-action 12-minute spell late in the opening period - three of them going the way of the Magpies.
Ben Davies seized on an error from Chris Whelpdale to slam the opener through the legs of Posh keeper Joe Lewis from close range after 31 minutes.
And he quickly doubled the lead three minutes later with a high-class, right-footed finish from just inside the box after being released by Neal Bishop.
Posh needed only two minutes to reduce their arrears when Gaby Zakuani rose to head home a deep Grant McCann corner and central-defensive partner Kelvin Langmead soon planted another glorious headed chance over.
Posh paid the price when Craig Westcarr grabbed a third County goal out of nothing two minutes before the break, beating Lewis with a bouncing 20-yard drive into the far corner.
But the hosts emerged determined to pull off another trademark second-half turnaround.
Tommy Rowe slammed a dipping long-range half-volley against the bar before Craig Mackail-Smith prodded in from an acute angle in the 59th minute after a mis-hit McCann free-kick fell perfectly for him.
But McCann's dismissal eight minutes later for a crunching foul on Alan Judge ultimately proved to be Posh's undoing.
Ricky Ravenhill incredibly escaped a second yellow card when hauling down Mackail-Smith on the edge of the box moments later but did receive his marching orders in stoppage time for kicking the ball away.
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