Robbie Simpson scored within seconds of his introduction as MK Dons came from behind to draw 1-1 with Grimsby Town on Tuesday night.
Simpson rose highest at the far post to nod home George Williams' cross barely a minute after the restart, cancelling out Jordan Cook's first half opener.
Grimsby deservedly led at the interval too, capitalising on Dons lethargic start and intent to sit deep. But a double change at half time breathed new life into Dons in the second period, and they could have won it late on but Dons' goal-mouth scramble fell just wide of the mark.
The result sees Dons slip to fifth in the table, still undefeated and two points behind Saturday's visitors Exeter City who lead the way.
Paul Tisdale named an unchanged side to the one which started the 0-0 draw against Crewe on Saturday, with Ouss Cisse keeping his spot in the side behind Kieran Agard. David Kasumu was named among the substitutes following Mathieu Baudry's late red card at the Alexandra Stadium as the only change.
Such has been the custom under Paul Tisdale, Dons appeared happy in the opening half hour, to allow Grimsby to pile forward in number and rely on sheer numbers in the penalty area to keep them out. Jake Hessenthaler twice had strikes blocked by Dons bodies, though he did force Lee Nicholls into a low save to his right to deny him the opener.
Dons' luck at the back would eventually wear out on 35 minutes when the visitors finally got their reward. Breaking into the area down the right flank, Martyn Woolford got his shot away but Nicholls could only parry it into the path of Jordan Cook, who needed no second invitation to smash home from close range to give Grimsby the lead.
Callum Brittain, who appeared to have forgotten his shooting boots at Crewe on Saturday, was not shy in chancing his arm this time around and twice came closest to finding the net for the home side, but both were deflected and only one really tested James McKeown in the Grimsby net.
Tisdale made a double change at the break, bringing off Alex Gilbey and Ryan Watson in favour of Baily Cargill and Robbie Simpson, and the latter made an immediate impact by netting the equaliser within seconds of coming on, heading home George Williams' cross.
Simpson nearly completed a remarkable turnaround just two minutes after his equaliser when he raced through on goal, forcing a fine stop from McKeown to deny Dons the lead.
The changes and indeed the goal breathed life into Dons as they took control of the game. Simpson again was at the heart of things when he rose high to nod across goal for Jordan Moore-Taylor, promoted to a midfield role in the second half, but it was just over his head.
Dons were given a huge boost with eight minutes to go when Paul Dixon was shown a straight red card for his dangerous challenge on Moore-Taylor on halfway, but incredibly didn't score when Agard, Simpson and Cargill scrambled for it in the six yard box with two minutes to go, somehow seeing it go wide of the upright.
Referee: Peter Wright
Attendance: 6,800 (610)
MK Dons: Nicholls, Williams, Moore-Taylor, Walsh, Lewington, Brittain, Houghton, Gilbey (Cargill 46), Watson (Simpson 46), Cisse, Agard
Subs not used: Moore, Hancox, D'Ath, Kasumu, Asonganyi
Grimsby Town: McKeown, Dixon, Welsh, Hessenthaler, Hooper (Vernam 58), Cook, Famewo, Clifton (Hendrie 73), Woolford, David, Whitmore
Subs not used: Robles, Wright, Rose, Thomas, Russell
Booked: Cargill, Whitmore, McKeown, Famewo
Sent off: Dixon