Hopes of European glory came crashing down to earth in the Russian capital tonight.
Requiring a victory over Dinamo Moskva, the loss of a goal after only two minutes turned an uphill struggle into one of mountainous proportions.
As Peter Houston's side chased the game, the Russians scored twice more before the break, and added two more in the second half.
But the 5-0 defeat was harsh justice on a United side that simply never gave up.
Even before a ball was kicked, there was bad news for the travelling Arabs who numbered around 250 with Sean Dillon ruled out due to a groin strain that forced his withdrawal at half-time in the game against Hibs. Brian McLean replaced him in central defence, but otherwise it was the same side that had acquitted themselves so well in the first leg against the Russians and in the SPL opening victory over Hibs.
In the wake of Dinamo coach Sergei Silkin's departure after slumping to straight defeats in their three opening league games, caretaker coach, Dmitri Khokhlov, placed in temporary charge, rang the changes.
Out went goalkeeper 25-year-old Anton Shunin, who didn't inspire confidence when under pressure at Tannadice. Taking over was the hugely more experienced 38-year-old Roman Berezovsky.
Immediately in front of him, Croatian international centre-back Gordon Schildeneld dropped to the bench with Argentinian Leandro Fernandez his replacement.
Painfully, it all went pear-shape for the tangerines by losing a goal inside two minutes!
A sublime precision pass from a central area by Artur Yusupov found Marko Lomic wide left
He cut the ball back across the box and Igor Semshov's first time strike from just inside the area left Rado Cierzniak helpless.
Spurred by this it was mostly one way traffic towards the United goal.
Russian international Kokorin's cheeky chip from the corner of the box as he tried to catch the united keeper wasn't too far away.
At the other end, any action was extremely spasmodic, though Daly did get his head to a Willo Flood cross on the quarter-hour but Berezovsky wasn't really tested.
Already having a mountain to climb, it became mission impossible midway through the first period when Dinamo again sliced open the Tannadice rearguard with a sweeping move down the left.
Hungarian 16 million Euros man Dzsudzsak suddenly burst on the scene with a surging run down the left before lofting the ball across to Kokorin, who powered home a header for the Russians' second.
Keith Watson was booked for downing Dzsudzsak two minutes later then Gary Mackay-Steven was clattered by Vladimir Rykov, earning the Russian a caution.
With half-an-hour, Cierzniak brilliantly blocked Kokorin after he had broken clear.
The United keeper was back in action two minutes later when Kokorin picked out his skipper Kevin Kuranyim but the Cierzniak, at full stretch, palmed away his effort.
For a change, it was the Pole's opposite number, Berezovsky, who was in the thick of the action, failing to deal with a Daly header, and only just preventing it landing at the feet of Johnny Russell.
But that was too good to last and five minutes from the interval, Artur Yusupov sped clear before rolling the ball past Cierzniak.
United's best effort of the opening period came just before its completion, Willo Flood's curling free-kick from 25-yards being tipped over by the home keeper.
The visitors started the second period with Russell firing over, but on 50 minutes, Kuranyi ought to have added a fourth missing the target with his header when it appeared simpler to score!
Then it was Kokorin's turn to be profligate in front of goal, unbelievably firing over with only Cierzniak to beat. Knowing the tie was in the bag, Dinamo took off Yusupov, Dzsudzsak and Rykov with 27 minutes left.
But United weren't lying down and Richie Ryan went close on 69 minutes a drive that went inches over. With eight minutes left, Kuranyi contrived the biggest howler of the evening, miscuing his shot over the bar from right in front of goal.
However, there was no further mercy from the home side as sub Aleksandr Sapeta surged through the heart of the United rearguard with seven minutes to go, and dinked the ball over Cierzniak.
Sapeta then rubbed further salt in Tannadice wounds with a raging 30-yarder into the top corner.
Summary:
A night to forget as this defeat brought us our heaviest ever defeat in European competition!
Man of the Match: With so many players having an uncharacteristic off-night, Rado Cierzniak was the one stand-out. Blameless for any of the goals, but for him the scoreline would have been even more embarrassing!
Dinamo Moskva: Berezovsky, Wilkshire, Fernandez, Rykov (Schildenfeld 62), Lomic, Kokorin, Semshov, Misimovic, Yusupov (Sapeta 62), Dzsudzsak (Bakkal 62), Kuranyi.
Subs not used: Shunin, Nyakhaychyk, Noboa, Bakkal, Chicherin.
Booked: Fernandez, Rykov, Yusupov, Sapeta
United: Cierzniak, Watson, Douglas, Gunning, McLean, Flood, Ryan, Rankin (Armstrong 59), Mackay-Steven (Dow 85), Russell (Gardyne 77), Daly.
Subs not used: Banks, Millar, Robertson, Barrett.
Booked: Watson
Referee: S Johannesson (Sweden).
Attendance: 9063