Riley Harbottle gave AFC Wimbledon a slender lead to take home in their League Two play-off semi-final against Notts County after scoring the only goal of an enthralling game at Meadow Lane.
The defender broke the deadlock and gave the Dons an advantage to try to build on at Plough Lane with his header in a chaotic second half that ended with Notts' Alassana Jatta being sent off for a lunging challenge on Alistair Smith.
Earlier, Notts were frustrated to have a penalty appeal waved away when a Conor Grant shot was blocked by Joe Lewis in a first half that went on to produce exceptional saves from both goalkeepers.
Alex Bass first denied Wimbledon's Ryan Johnson with a diving save to his left before Owen Goodman foiled a fiercely hit effort from Grant minutes later.
Grant should have done better too when he only had Goodman to beat when unmarked in the box, but the goalkeeper's sprawling save and a clearance by Harbottle as Jatta closed in on the rebound proved decisive.
Harbottle went on to nod the winner, while Jodi Jones hit the post and Grant had a late effort cleared off the line by Josh Neufville as Notts went in search of a leveller, before Jatta was shown a straight red card for a two footed tackle on Smith in stoppage time.
His sending off came as a huge blow to Notts' efforts to reach the Wembley final on 26 May, and compounded a miserable run for the Magpies who have now lost five of their past seven games.
Notts ended the regular season to the sound of boos at Meadow Lane when beaten by League Two title winners Doncaster Rovers on the final day a week earlier, and Magpies boss Stuart Maynard said he wanted what happened over 46 games of the campaign to "go out the window" ahead of the play-offs.
It was not until the 29th minute that the home crowd roared into life, as they demanded a penalty when Grant's half-volley appeared to hit the hand of Lewis.
Referee Thomas Kirk was unmoved, but it will undoubtedly go down as another controversial call made by an official in this season's English Football League play-offs.
Bristol City head coach Liam Manning fumed about referee Oliver Langford - who sent off Robins defender Rob Dickie in Thursday's Championship semi-final first-leg loss to Sheffield United - while earlier on Saturday, Stockport manager Dave Challinor called the decision to allow Leyton Orient's opening goal to stand in their 2-2 League One draw an "absolute shocker".
It was a moment that sparked the game to life, with both sides going on to create their best chances of the first-half after that.
Former Dons keeper Bass stopped Johnson from putting the visitors ahead with a glancing header minutes after the shouts for handball, while Grant demanded an even better save of Goodman when his thumped effort from a Matt Palmer pass looked destined for the bottom corner.
Goodman's early second half save to once again keep Grant out was the pick of the night's outstanding stops, while Harbottle's reactions to slide in and sweep away what would have been a tap-in for Jatta was just as crucial.
Harbottle broke the deadlock himself at the other end, meeting a deep cross from Jake Reeves to beat Bass.
Jones rattled the post from 20 yards out as Notts looked to quickly restore parity, before Goodman went on to make it a hat-trick of saves from Grant when the ball had fallen kindly for the midfielder in the box.
Notts continued to push for an equaliser, with 37-year-old former Sheffield United and Ipswich Town striker David McGoldrick - who limped off late on - a source of endless endeavour on a night that finished with late drama.
Grant was involved twice, first drawing penalty appeals when going down in a tackle from Jake Reeves before he saw a goalbound effort in the 88th minute cleared by Neufville.
Then in the 95th minute, Jatta's reckless challenge on Smith meant the hosts finished with 10 men and now have their leading scorer ruled out for Saturday's return tie.
