Match ends, Walsall 1, Barnsley 3.
Barnsley booked their place at Wembley in the League One play-off final with an ultimately comfortable play-off second-leg win at Walsall.
Adam Hammill's early close-range strike for the visitors was followed by Ashley Fletcher's second-half effort.
Walsall's Jordan Cook curled in a late right-foot reply from outside the box but Josh Brownhill pounced on an error to complete a 6-1 aggregate victory.
The Tykes will now face either Millwall or Bradford in the final on 29 May.
That meeting will be the Johnstone's Paint Trophy winners' second Wembley trip of the season.
After finishing 10 points adrift of Walsall in the end-of-season League One table, Barnsley's progression to the final also means all the Football League teams who most narrowly missed out on automatic promotion have now failed in the playoffs.
The Saddlers follow the example of the Championship's third-placed side Brighton and League Two's fourth-placed side Accrington Stanley in bowing out in the semi-finals - having all missed out on automatic promotion on the final day of their regular season.
Attack, attack, attack...
Walsall went for an attacking 3-5-2 formation in a bid to turn it round following Saturday's 3-0 first leg defeat at Oakwell, but they were to be outclassed in Bescot's battle of the caretaker bosses.
Jon Whitney's Saddlers needed an early goal to stand a realistic chance of rescuing the tie. But, instead, Hammill slotted home for Paul Heckingbottom's side on 17 minutes when Walsall failed to clear Conor Hourihane's cross.
Top scorer Bradshaw and Jordy Hiwula wasted good chances, both miscuing, after an error by Barnsley defender Alfie Mawson. And, from Romaine Sawyers' cross with the outside of his right foot, Adam Davies had to fly to his right to pull off a one-hand save to keep out Bradshaw's header.
But too much of Walsall's shooting from in and around the box was hurried and off target.
And Fletcher's pace and power at the other end proved a lot more likely to bring another goal, long before his 66th-minute second settled it.
Walsall did at least score the goal of the night when substitute Cook curled in a right-foot stunner from just outside the box with five minutes left.
But Walsall's Rico Henry's late blunder allowed Brownhill to steal an injury-time third and restore the Tykes' five-goal advantage.
Walsall interim head coach Jon Whitney told BBC WM: "They deserved it over the two legs. There was no luck involved. They put in a real shift for their manager.
"I was disappointed on Saturday at how we played, but not tonight. My lads put a shift in and Barnsley had to defend very well.
"Maybe the disappointment of not making it after putting in that fantastic performance at Port Vale on the final day of the season had an effect on us.
"But we've now tasted how close we have come and we want to do it again. This experience can only be a positive to my players."
Barnsley caretaker boss Paul Heckingbottom told BBC Sport: "The first step was to get to the play-offs, the next step was to get to Wembley and we've done that.
"We've still got a job to do, whoever it is against. I'll be watching tomorrow night and then we'll start planning.
"The lads are perhaps a bit more subdued at getting to Wembley than they were last time as we've been there before this season.
"But I think having been there so recently will benefit us. We know what the venue is like now, we know what to expect and we'll be more than ready for it."
- 6DowningBooked at 45mins
- 3TaylorSubstituted forCookat 63'minutes
- 31Hiwula-MayifuilaSubstituted forLalkovicat 72'minutes
- 9BradshawSubstituted forFordeat 83'minutes
- 20HammillBooked at 12minsSubstituted forChapmanat 74'minutes
- 9WinnallSubstituted forToneyat 70'minutes
- 18FletcherSubstituted forMcCourtat 70'minutes
- Darren Deadman
- Shots on Target
Second Half ends, Walsall 1, Barnsley 3.
Foul by Jordan Cook (Walsall).
Alfie Mawson (Barnsley) wins a free kick in the defensive half.
Jordan Cook (Walsall) wins a free kick on the left wing.
Foul by Jak McCourt (Barnsley).
Goal! Walsall 1, Barnsley 3. Josh Brownhill (Barnsley) right footed shot from the right side of the six yard box to the centre of the goal. Assisted by Lloyd Isgrove.
Foul by Rico Henry (Walsall).
Lloyd Isgrove (Barnsley) wins a free kick on the right wing.
Goal! Walsall 1, Barnsley 2. Jordan Cook (Walsall) right footed shot from outside the box to the top right corner. Assisted by Romaine Sawyers.
Substitution, Walsall. Anthony Forde replaces Tom Bradshaw.
Attempt missed. Ivan Toney (Barnsley) left footed shot from outside the box misses to the right. Assisted by Harry Chapman.
Substitution, Barnsley. Harry Chapman replaces Adam Hammill.
Foul by Adam Chambers (Walsall).
Jak McCourt (Barnsley) wins a free kick in the defensive half.
Attempt missed. Ivan Toney (Barnsley) left footed shot from more than 35 yards misses to the right.
Substitution, Walsall. Milan Lalkovic replaces Jordy Hiwula-Mayifuila.
Offside, Barnsley. Adam Hammill tries a through ball, but Ivan Toney is caught offside.
Substitution, Barnsley. Ivan Toney replaces Sam Winnall.
Substitution, Barnsley. Jak McCourt replaces Ashley Fletcher.