Walsall beat Chesterfield with a late flourish to secure their place in the League Two play-off final at Wembley.
Jubilant fans entered the pitch after Levi Amantchi scored in added time, moments after Armando Dobra's equaliser, as the Saddlers followed up Sunday's 2-0 victory with a second win over the Spireites in a week.
Substitute Charlie Lakin was set up by fellow sub Albert Adomah just six minutes after the pair came off the bench to give the hosts the lead on the night and open up a three-goal lead with less than 10 minutes remaining.
Dobra scored a consolation for the visitors in added time, before Amantchi made up for an earlier miss to send the Walsall fans into bedlam with next to no time left.
The restart had to be delayed as supporters came on to the pitch to celebrate, with flares dropped on the turf.
The Saddlers will face the winner of AFC Wimbledon and Notts County, who play on Saturday, in the final on Monday, 26 May.