Dimitri Papadopoulos' shocking miss from close range cost Burnley the chance of taking three points off Ipswich and in the end had to settle for a 1-1 draw.
The Greece international failed to find the target from all of four yards after being picked out by Glen Little five minutes from time.
At first glance, a draw against a side who had won their last four games - scoring 13 goals in the process - would not appear to be too disappointing a result.
But it said much for the ease of the opportunity which Papadopoulos squandered that Ipswich's Joe Royle will be the more relieved of the two managers.
Royle had seen Pablo Counago open the scoring after 22 minutes - the first of his 14 goals this season away from Portman Road - extending Ipswich's scoring record to 13 consecutive games.
Robbie Blake equalised for Burnley from the penalty spot, sparking a late rally which culminated in Papadopoulos' terrible miss.
Given the contrasting fortunes of these sides going into the game - Burnley boasted just one win in five matches; Ipswich were unbeaten in seven - it was the hosts who made the early running.
Ipswich goalkeeper Andy Marshall was forced into a stunning save to keep out Ian Moore's header from Cook's free-kick, while Blake sent a powerful left-footed drive over the crossbar.
Burnley's failure to defend set-pieces proved their undoing, though, Counago supplying the emphatic close-range finish after Jim Magilton had flicked on Darren Ambrose's corner.
Matt Holland went close to doubling Ipswich's advantage, only to see his header blocked by Cook, although Glen Little - back from suspension - and Blake responded for Burnley from distance.
It said much for Ipswich's impressive discipline and adherence to Royle's tactics that those efforts were the closest Burnley came to restoring parity before the break.
Jermaine Wright stung Nik Michopoulos' hands shortly after the restart with an audacious 25-yard volley, and the two Bents, Darren and Marcus, shot wide after Ipswich had withstood a period of Burnley pressure.
But Burnley emerged from a tricky spell of their own to level matters in the 66th minute, Blake sending Marshall the wrong way from the spot after the goalkeeper had tripped Ian Moore.
Blake was coolness personified as he slotted the ball into the bottom right-hand corner, but credit must also go to Alan Moore, who had picked his namesake out with a delightfully weighted through-ball.
Although Blake was only narrowly off target with a free-kick minutes later, Burnley were indebted to Michopoulos's smart reactions in keeping out Tommy Miller's strike.
It needed a goalline clearance from Albanian debutant Drissa Diallo, impressive throughout, to preserve the status quo, as well as sparing the blushes of Michopoulos, whose misjudgement in coming to claim a cross had presented Darren Bent with the ball on the edge of the area.
That was largely forgotten, though, after Papadopoulos' late howler.