Deadly Dipo Akinyemi inspired Ayr United to move six points clear at the top of the Championship on a big night in front of the BBC cameras.
The striker scored in both halves to take his tally for the season to 13 as the Honest Men withstood an Accies onslaught to register a massive three points.
And Ben Dempsey's late penalty put the seal on a rollercoaster contest which swung both ways on a thrilling night.
Akinyemi's early opener was cancelled out by a Steve Lawson penalty just after half time before the Ayr hitman bulged the net following great build up play from sub Finn Ecrepont.
Ecrepont then put through his own goal before Dempsey's late penalty capped a five goal thriller.
Ayr had rung the changes with a switch to 4-5-1 system - starting Paul Smith in midfield while Paddy Reading returned in place of the injured Frankie Musonda at left back.
And they got the perfect start when Akinyemi pounced on a slack pass from Accies striker Andy Ryan to streak clear and slot home.
Accies looked for a quick response and Akinyemi was needed to head clear a goalbound effort from Michael Doyle as the hosts pushed.
Jean-Pierre Tiehi then shovelled over from close range as the hosts continued to press during a strong response to falling behind.
Then came a huge flashpoint as Tiehi turned to fire home off the underside of the bar - TV replays showing the ball had clearly crossed the line - but the officials incredibly waved play on.
Andy Winter wasted another chance when firing high and wide as Ayr continued to ride their luck during a break-neck first half.
They made it to half time and Bullen introduced Sam Ashford for Smith as he reverted to a more orthdodox 4-4-2.
But Accies were handed a route right back into the game shortly after the restart when Winter tumbled under a Sean McGinty challenge to win a penalty, which Lawson converted.
The same player then blazed over from 12 yards as Accies threatened to turn the game on its head in quick fashion with Ayr struggling to keep pace.
But Ayr found a way to forge back ahead when Ecrepont - on for the injured Nick McAllister at right back - did brilliantly to cross for Akinyemi to fire home.
However, moments later, Ecrepont had put through his own goal when a wicked Dan O'Reilly cross caught him out at the backpost.
But Ayr were not to be denied and they surged straight to the other end, where O'Reilly turned sinner to pull back Alex Kirk for a spot kick which Dempsey converted to send the Ayr travelling support wild.
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