Cameron McGeehan chose a good time to score his first Scunthorpe goal as his late leveller forced a 2-2 draw with Rotherham in their Sky Bet League One play-off semi-final first leg at Glanford Park.
Joe Newell's goal 58 seconds after coming on looked like giving the Millers the advantage but McGeehan, on loan from Barnsley, bundled home from close range in the 88th minute.
Rotherham had twice led after Jon Taylor's early goal was cancelled out barely a minute later by a Michael Ihikewe own goal, but they will still be happy with the result and will be favourites to progress to Wembley when they host the second leg on Wednesday night.
McGeehan's late intervention does mean, though, that Iron remain undefeated under caretaker manager Nick Daws since he took over from Graham Alexander in March.
It was a tight start as both sides felt each other out before it burst to life with two goals in 76 seconds.
Warne's men went in front as ex-Dundalk midfielder Richie Towell's delightful ball set Taylor clear and the winger composed himself and found the back of the net with a low finish from 12 yards out in the 17th minute.
But their celebrations had barely ended by the time Scunthorpe were level.
Hakeeb Adelakun broke free down the right, played in Duane Holmes, whose clipped finish was going wide before being turned in to his own net by Ihiekwe when he had time to do better.
That gave the hosts a big lift and they almost took the lead a couple of minutes later, but Rory McArdle's downward header bounced up and hit the crossbar.
Scunthorpe continued to assert their authority after the break and McArdle had another fine chance but he headed Josh Morris' cross straight at Marek Rodak when anywhere else would have resulted in a goal.
Rotherham made a substitution to try and affect the game and it had an immediate impact as Newell needed only 58 seconds to put his side back in front.
Josh Emmanuel made a surging run down the right, his cross was miscued by Towell into the path of Newell, who rifled a low shot into the bottom corner in the 64th minute.
Scunthorpe had also made a change, bringing on goalkeeper Rory Watson to replace the injured Matt Gilks and his first touch was to pick the ball out of the back of the net.
The Millers were intent on keeping their lead a little bit longer than the first time, though they had Rodak to thank as he got down well to save Holmes' effort and then blocked Ivan Toney's follow-up shot.
Rotherham appeared to be holding out, even looking more likely to get a third, but they succumbed to an 88th-minute set-piece with McGeehan forcing home from close range to leave it all to play for.