A horror batting collapse saw them squander a superb start and hand the initiative to their rivals who ruthlessly cashed in.
The game should have been put beyond the UAE after Matthew Cross and Kyle Coetzer put on 138 for the first wicket.
Instead, the Scots slumped to 220 all out and the UAE batsmen, with their tails up, came out with all guns blazing to finish the job.
Openers Chirag Suri and Vriitya Aravind raced to 42-0 in just five overs with Gloucestershire’s Stu Whittingham conceding 26 in two wayward overs. They added a further 20 before Aravind gloved a catch to Cross off Hamza Tahir to give Scotland a bit of hope.
Dylan Budge picked-up the wicket of 18 year-old debutant Jon Figy but Suri had put his side on course for victory with 67 from 73 balls before he was caught in the deep off a Whittingham bouncer.
It was the last success for the Scots as an unbroken stand of 86 between Basil Hameed (63no) and Muhammad Usman (36no) carried UAE to an easy seven-wicket win with 6.1 overs to spare.
Earlier Scotland were given a fantastic start by Cross and skipper Coetzer who set the platform for what should have been a huge total. Coetzer led the way with a string of expansive shots as the Aberdonian pair punished the home bowlers.
Cross was content to play the supporting role, stroking four boundaries in a controlled 53 before he was first out.
The captain, meanwhile, hit eight boundaries and one maximum on his way to a superb 95 and looked poised for his fifth ODI century, only to hole out off the bowling of Palan Meiyappan.
Leg-spinner Meiyappan also removed Richie Berrington for a duck in the same over and the slump was in full swing.
The experiment of promoting George Munsey to No3 in a bid to cash-in on the bright start yielded just seven runs from 12 balls.
None of the middle order batsmen were able to make a substantial contribution with Budge’s 24 the best effort.
In the end, Scotland failed even to bat their full quota of 50 overs, bowled out with nine balls remaining having lost all ten wickets for just 82 runs.
Coetzer’s side have now lost three of their first eight fixtures in World Cup League 2 and lie three points behind leaders USA.