Scunthorpe substitute Cameron McGeehan scrambled a late equaliser as the Iron twice came from behind to record a 2-2 draw with Rotherham in their League One play-off semi-final at Glanford Park.
The Millers took the lead when Jon Taylor expertly slid home Richie Towell's pass from midfield (17), but just 26 seconds after the restart, Michael Ihiekwe turned Duane Holmes' dinked shot into his own net (18).
Substitute Joe Newell struck with his first touch to hand his side a 2-1 advantage a few minutes after the hour (64), but McGeehan capitalised on some lackadaisical defending from the visitors to level proceedings late on (89).
Scunthorpe: Gilks (6), Clarke (6), McArdle (6), Wallace (6), Townsend (6), Adelakun (7), Ojo (6), Yates (6) Morris (6), Holmes (6), Toney (7)
Subs: Watson (4), McGeehan (7), Hopper (n/a)
Rotherham: Rodak (6), Emmanuel (7), Ihiekwe (5), Wood (6), Mattock (6), Taylor (7), Vaulks (6), Palmer (6), Towell (6), Williams (8), Smith (6)
Subs: Newell (7), Ajayi (5), Forde (n/a)
Man of the match: Ryan Williams
The result extends the hosts' unbeaten run to eight games and leaves the tie finely poised ahead of Wednesday night's return fixture at the New York Stadium.
Paul Warne's men - backed by a raucous 1,600 away following - took the game to the hosts from the whistle, delivering long balls into the final third for target man Michael Smith, though they had little success in the opening stages.
After 17 minutes though, one of those long balls forward helped them to the first goal, when Towell's aerial ball was slid home by Taylor after the winger had held off the challenge of defender Murray Wallace.
The game then exploded into life and just 26 seconds after the restart, the Iron were back in the tie.
Hakeeb Adelakun touched the ball through to Holmes, who lifted the ball over Rodak; the effort seemed to be heading wide, but Ihiekwe's scuffed clearance trickled over the line.
Caretaker Scunthorpe boss Nick Daws made five changes to the side that drew 1-1 with Bradford on the final day of the regular season, with Marnick Vermijl, Cameron Burgess, Neal Bishop, Cameron McGeehan and Lee Novak making way for Jordan Clarke, Murray Wallace, Funso Ojo, Duane Holmes and Ivan Toney.
Just the one change for the Millers, though, as Brighton loanee Richie Towell took the place of David Ball.
Nick Daws' men had responded well to falling behind, but they were dealt a major blow inside 15 minutes of the restart when goalkeeper Matt Gilks sustained an injury during an attempted throw from his 18-yard box.
They fell behind once more when Newell slammed home Josh Emmanuel's cross at the far post, but the hosts rallied and were rewarded for their tenacity in the final minute of normal time when McGeehan poked Ivan Toney's flick goalwards, with Ihiekwe's final touch taking the ball over the line.
Man of the match - Ryan Williams
Rotherham's Australian winger grew into the game on Saturday lunchtime and proved to be a handful on the left hand side. The final ball was slightly lacking at times, but the 24-year-old was a livewire on the flank and will be a key part of any hopes the Millers have of triumphing in the second leg on Wednesday evening.
Nick Daws: "It sets it up nicely, immensely. I think me and Warney were both saying with about 85 minutes to go, that we'd take a draw at that point. Joking apart, I thought it was two very good teams with contrasting styles going at each other for 90 minutes. I thought my team showed an immense amount of character to get the equalising goal after bouncing back from the first goal as well."
Paul Warne: "I'm pretty happy; I would've taken a 2-2 draw beforehand. It was pretty reflective of the game, it was edgy obviously, I thought it would be a draw, I though there'd be goals. We're pleased with the way we played in patches - could've been better at times. But it takes it back to Wednesday night at our stadium so it'll be a good game."
When's the second leg?
Rotherham host Scunthorpe at the New York Stadium on Wednesday night, live on Sky Sports Football from 7.30pm. Kick-off is at 7.45pm.