Dundalk were making solid headway before and after they zoned out during a costly 10-minute spell that torpedoed their European hopes.
And, sitting just four points clear of the Premier Division’s relegation playoff and 11 points off a guaranteed European finish, they have it all to do to return here next year.
Matus Bero and Yann Gboho scored either side of the half hour to grind Dundalk’s early momentum to a shuddering halt.
But Vinny Perth’s men were the more adventurous side either side of that dire double whammy where they conceded soft goals that will haunt them.
Even when they shipped those killer goals, it never felt like a lost cause because they were brilliant at times with wave after wave of unrelenting attacks.
Dundalk might have lacked street smarts at times earlier in the game, but they closed it out with tremendous spirit and desire.
And Vitesse were hanging on for dear life at the death as Dundalk peppered their goal with every attack in the pursuit of extra-time at least.
Pat Hoban’s penalty with 20 minutes to go provided a barnstorming finish while Michael Duffy, Raivis Jurkovskis and David McMillan almost forced extra-time.
Dundalk have enjoyed great European nights in Tallaght and this could have been another, but for that self-inflicted implosion before the break.
But perhaps when you have a Michael Duffy goal scrubbed out for offside after just 40 seconds, you just sense it’s not going to be your night.
Vitesse were certainly smarting at how Dundalk were allowed to dominate large spells of last week’s game in Holland despite going a goal behind.
And they arrived here with a determination to snuff their hosts out early on. But the opposite happened in the opening exchanges.
With less than a minute played, Will Patching split the Dutch defence with a perfectly weighted ball that Duffy drilled home at the near post.
But it was deemed offside.
Still, Duffy was a man on a mission and caused all sorts of bother to Vitesse down that left flank.
A low cross into Hoban was crying out to be punished but the striker, under pressure from Alois Oroz, couldn’t make the desired connection at close range.
Like Duffy, Hoban was always a threat.
He outmuscled Oroz to a ball down the right flank and cut in before flashing a wicked drive that deflected a yard wide of Markus Schubert’s post.
From the corner, Patrick McEleney’s thunderous shot was on target before a Vitesse intervention and, from the subsequent corner, Sonni Nattestad heade just over.
Vitesse were lucky to survive and hadn’t offered a great deal in attack up to that point. And yet from nothing, they snatched the lead in the 28th minute.
Nikolai Frederiksen’s shot looped off Andy’s Boyle challenge and with Alessio Abibi in no man’s land, Slovakian international Matus Bero slotted home.
It might have been curtains moments later had Boyle not stuck out a boot to deflect Million Manhoef’s scrambled effort onto the post in a crowded box.
But it was effectively all over once Yann Gboho bagged Vitesse’s second seven minutes before half-time.
Frederiksen had far too much time and space down the left and Gboho timed his run to perfection and slotted a cool side-footed finish past Abibi.
Thereafter, Vitesse retreated to protect their lead and allowed Dundalk to build a platform from which to launch one final assault.
Hoban’s penalty with 20 minutes remaining - after Sondre Tronstad fouled Duffy - brought the house down.
And Duffy, Raivis Jurkovskis, Greg Sloggett and David McMillan almost provided the fairytale finish to force extra-time, but all were denied.
Oh the agony of it all.
DUNDALK: Abibi 6; Dummigan 7, Boyle 6, Nattestad 6 (Jurkovskis 73, 6), Leahy 6; Stanton 6 (Kelly 58, 7), Sloggett 7; McEleney 7, Patching 7 (McMillan 72, 6), Duffy 8; Hoban 7.
VITESSE: Schubert 6; Bazoer 7, Doekhi 6 (Domgjoni 84, 5), Oroz 6; Wittek 6, Gboho 7 (Hajek 63, 5), Tronstad 7, Manhoef 7 (Vroegh 78, 5); Bero 7, Darfalou 6, Frederiksen 6 (Vonmoos 63, 5).
Referee: Alain Durieux (Luxembourg)
