Super sub Magaye Gueye stepped off the bench to score a dramatic 95th-minute equaliser as Millwall extended their unbeaten run to 12 games with a gutsy draw at Sheffield Wednesday.
The Lions had been heading to their first defeat since March as they trailed to Chris Maguire's 56th-minute free-kick heading into the dying seconds of Tuesday night's match.
Shaun Williams had seen his 85th-minute penalty hit the woodwork and it looked like curtains for Ian Holloway's side, but sub Gueye had other ideas and sent the travelling fans wild with a thumping last-gasp leveller following a great counter-attack.
A draw was just about the fairest result from a game in which both The Lions and Owls created chances in equal parity.
Lions boss Ollie had made just one change to the team that recorded an excellent 1-0 win at Fulham the previous Saturday, with Lee Gregory handed his first Championship start for The Lions in place of Ricardo Fuller, who dropped to the bench.
Left-back Matthew Briggs was named as one of the seven subs in place of Nicky Bailey, who will be sidelined with a calf injury until September.
Both Millwall and Sheffield Wednesday went into Tuesday night's game unbeaten this season, and neither team had conceded a goal either.
Something was always going to have to give - and it could have been Millwall's proud defensive record after just three minutes when Wednesday's Steve May stole in behind the backline, but he drilled the ball wide from eight yards.
At the other end The Lions' first decent scoring chance came on 12 minutes when Williams was fouled 20 yards out and Lee Martin's curling free-kick dropped just wide of Keiren Westwood's post.
The home side then enjoyed their best spell of first-half pressure with Atdhe Nuhiu powering a header over and May twice getting into dangerous positions, but failing to find the final decisive touch.
Jacques Maghoma went to ground easily after weaving his way into the box seven minutes before the break but his appeal for a penalty were quite rightly waved away by referee Nigel Miller.
Having admirably dealt with a flurry of attacks from Wednesday, The Lions finished the opening half on the front foot and created a couple of half-chances themselves.
A deft touch from Gregory picked out Martyn Woolford, but he fired an angled shot over the bar. Gregory then went close himself when he intercepted a sloppy back-pass from Glenn Loovens just inside the danger zone. Owls keeper Westwood reacted smartly though and averted the danger by coming off his line quickly to collect the ball.
With both defences in such dominant mood, a goal-less first 45 minute was probably not entirely a surprise.
However within 11 minutes of the restart Wednesday finally ended Millwall's proud run of four clean sheets with the opening goal. Martin was harshly penalised for handling on the edge of the penalty area when the ball appeared to hit his chest, but up stepped Maguire to curl the resulting free-kick beyond the wall and reach of keeper David Forde.
Millwall's response was immediate, making a double change to bring Fuller and Gueye on for Gregory and Jimmy Abdou.
The move sparked Holloway's men into life and just moments after his introduction Gueye jinked his way past two defenders before slipping the ball into the path of fellow sub Fuller, but his effort was blocked and the danger cleared.
Woolford went even closer to equalising midway through the half when he hit a stinging 25-yarder that flew narrowly over.
A neat, flowing break involving the two Scotts - McDonald and Malone - ended when the latter's slipped through pass to Fuller caught the Owls rearguard napping, but the Millwall striker had timed his run a fraction early and the linesman's flag brought a promising move to an end.
However The Lions were handed a great opportunity to level with five minutes remaining when Martin went crashing to the ground under a challenge by keeper Westward. Up stepped Williams to take the spot-kick, but his low shot crashed against the foot of the right hand post and unfortunately no Lions player reacted quickly enough to connect with the loose ball.
At such a late stage in the game to most teams, that would probably have been that. But not these Lions. Not this team.
Nothing epitomised Millwall's never-say-die attitude greater than the manner of the equalising goal when it arrived deep into the fifth minute of injury time. McDonald kept battling away by the corner flag as Wednesday tried to play out the final few seconds of the game. His persistence paid off enough to get a touch of the ball and play it into the path of Woolford, who in turn despatched a long raking pass that found Carlos Edwards on the right. He slipped the ball to Fuller, who laid it into the path of Gueye and the sub lept his cool, side-stepping two challenges before lashing the ball into the roof of the net.
It was a smashing goal and a well deserved point for Millwall, who now have Rotherham United in their sights this Saturday looking to make it 13 games unbeaten.