Walsall secured their spot in the League Two play-off final by beating Chesterfield 2-1 at the Poundland Bescot Stadium, completing a 4-1 aggregate victory.
The Saddlers, who held a 2-0 advantage from the first leg, defended well and sealed their progress with a close-range finish from Charlie Lakin nine minutes before the end.
Although Armando Dobra scored a stoppage-time goal for Chesterfield, Levi Amantchi responded quickly to ensure Walsall won the match as well as the tie overall.
Amantchi's goal led to pitch invasions, with the second happening after the final whistle, marking Walsall's date with either Notts County or AFC Wimbledon at Wembley on May 26.
Walsall, who squandered a 12-point lead in League Two, started strongly in search of an early goal to seal the deal.
Jamie Jellis had an early chance from the right but was denied by Chesterfield keeper Ryan Boot.
Overturning a two-goal deficit from the first leg to reach the final had only happened four times in nearly 40 years of the EFL play-offs.
Chesterfield started to pose a threat, with Dobra testing Walsall keeper Tommy Simkin with a powerful shot from distance.
Bim Pepple tried to break through for Chesterfield but was well dealt with by the home defense, and his attempts from the edge of the box were off target.
As the first half drew to a close, Pepple had another opportunity but failed to trouble Simkin with a weak shot.
Chesterfield thought they had scored after the break, but Jenson Metcalfe's goal was disallowed due to a handball in the build-up.
Walsall had a chance to seal the match with 17 minutes remaining but Amantchi couldn't beat Boot when one-on-one.
However, Lakin found the net in the 81st minute, tapping in Adomah's cross to put the result beyond doubt.
Chesterfield pushed for a late comeback, but McFadzean and Colclough were denied by the Walsall defense.
Despite late attempts from both teams, Walsall had the final say with Amantchi scoring from Adomah's cross a minute after Dobra's consolation goal.