Rotherham United hold the League One play-off advantage against Scunthorpe United despite suffering a late setback at Glanford Park.
The Millers head into next Wednesday's home semi-final second leg as favourites to reach the Wembley final after securing a 2-2 draw.
It could have been even better, but Paul Warne's men conceded an equaliser in the 88th minute when they looked set to beat the Iron for the third time this season.
Super-sub Joe Newell had come on in the 63rd minute and scored within 58 seconds of his entrance after Jon Taylor's 17th-minute opener had been cancelled out by Michael Ihiekwe's own goal a minute later.
However, Cameron McGeehan came off the bench to score his first ever Scunthorpe goal two minutes before the end of regulation time to take the shine off Rotherham's day.
The Millers made the better start and were in front after 17 minutes as Richie Towell's measured chip over the defence played in Taylor and the winger ran on and made no mistake.
Their lead had lasted barely a minute when Michaerl Ihiekwe turned the ball into his own net. Duane Holmes' shot had beaten Marek Rodak and might have been going wide. Ihiekwe looked set to clear any danger until his tangled feet gifted the home side an equaliser.
Rory McArdle clipped the Rotherham bar from a corner soon after, but the visitors reasserted themselves after a five-minute spell of Scunthorpe pressure and, in the 36th minute, Towell should have done better than blaze over from the edge of the penalty area.
Scunthorpe stepped up the pace after the break and Rodak held on to McArdle's header when Hakeeb Adelakun whipped in a dangerous cross.
But it was the visitors who swept back into the lead in the 64th minute. Newell's first touch saw him rifle a superb shot past goalkeeper Rory Watson, who had just replaced the injured Matt Gilks, right in front of the sold-out away end.
Josh Emmanuel had made a surging run down the right and his cross found Newell in space with help from Towell's miskicked volley.
As the game hotted up, Rodak kept Rotherham in front three minutes, saving from Holmes, who was clean through, with Ivan Toney putting the rebound into the side netting from a tight angle.
Ryan Williams was close to a third with a bending 85th-minute effort before McGeehan forced the ball in from close range.
It was a disappointing end to a good day for the Millers who will be relishing the return clash at AESSEAL New York Stadium.
Scunthorpe United (4-4-1-1): Gilks (Watson 61); Clarke, McArdle, Wallace, Townsend; Adelakun (McGeehan 74), Ojo, Yates, Morris; Holmes; Toney (Hopper 90+3). Subs not used: Bishop, Novak, Vermijl, Burgess.
Rotherham United (4-1-4-1): Rodak; Emmanuel, Ihiekwe, Wood, Mattock; Vaulks; Taylor (Newell 63), Towell (Ajayi 72), Palmer, Williams (Forde 90+4); Smith: Subs not used: Price, Purrington, Ball, Lavery.
Goals: Taylor 17, Newell 64 (Rotherham); Ihiekwe og 18, McGeehan 88 (Scunthorpe).
Referee: Tim Robinson (West Sussex).
Attendance: 6,591 (16,01).