Dundee put in a dominant display to earn their spot in the Premiership as Kilmarnock crashed out of the top flight Rugby Park play-off showdown.
The Ayrshire men were already on the back foot as they went into the second leg narrowly trailing, but early goals from Danny Mullen and Lee Ashcroft got James McPake's side off to the perfect start.
Kyle Lafferty netted from the spot but it proved to be nothing more than a consolation as the 4-2 aggregate defeat ended the hosts' 28-year stay in the top flight of Scottish football.
Tommy Wright's lacklustre side got off to a nightmare start on their own patch as a quick counter attack allowed Paul McMullan to unlock the Killie defence, and Mullen calmly slid the ball under Colin Doyle.
Things went from bad to worse minutes later as a defensive mix-up allowed Lee Ashcroft to head in the second goal of the night.
Lafferty dispatched the spot-kick after Adam Legzdins wiped out Rory McKenzie in the area but his team-mates never looked like adding to the comeback effort.
And in the end Dundee cruised to a 4-2 aggregate win to secure their first Premiership season since relegation in 2019.
The Kilmarnock fans were back in for the first time this season, and after a historic disappointment, most will wish they weren't back just yet.
Defensive woes sum up the season
The second goal for Dundee is a comedy of errors from the home defence. A simple corner into a dangerous area saw Kirk Broadfoot jump in front off Lee Ashcroft, before the towering attacker thumped the header past Doyle.
Whether it's been under Alex Dyer or Tommy Wright, Killie haven't looked composed at any stage at the back.
In contrast, Dundee looked solid and stood firm throughout the game in what could have been a tricky away tie. The defensive issues were again costly when the team needed it most.
It will be interesting to see how that back-line fares in the Premiership - they did far better against Lafferty and Co than most of the bottom six teams.
Dee day
For James McPake it was all about promotion. The Dundee boss couldn't mount a challenge on Hearts this season but with the likes of Charlie Adam at the heart of the midfield, a Premiership return would have been essential for the owners.
The former Dee defender was under mounting pressure amid mixed results during his two-year spell in the dugout, but the board have now been rewarded for their faith in the 36-year-old by becoming only the third side to earn top flight promotion through the playoffs.
And neither Livingston nor Hamilton did it in such dominant style.
Now they have Dundee derbies to look forward to as they look to a return to the big stage.
What's next?
Kilmarnock aren't a club that is used to being outside of the upper reaches of Scottish football. Following their playoff drubbing, how will the club respond when they aren't among the big boys?
It's been an unbelievable fall from grace from the Steve Clarke era. When Clarke left for Scotland, the club were in third spot and dreaming of a European run.
Two years later, three managers down, and one relegation. Will Tommy Wright remain, and if not who takes the job? Talisman and scorer Kyle Lafferty has been one of the standouts in a dreadful season, but he's out of contract now. So, how many players stay?
It now looks to be a massive rebuild that is needed at Rugby Park ahead of their Championship bow if they are to make a quick-fire top flight return.
