Captain Andy Balbirnie hailed Paul Stirling as "world class" following a century against the UAE.
However, Stirling's knock of 131 wasn't enough for Ireland, who lost the first of four one-day internationals with the Emirates by 6-wickets.
Ireland set a target of 270 in Abu Dhabi on Friday, one the UAE surpassed with six balls remaining of their innings.
Centuries for Chundangapoyil Rizwan and Muhammad Usman helped steer the UAE to victory.
"It's quite tricky to know where the momentum of the game turned," Balbirnie said afterwards, "We kept them under wraps pretty well.
"The [run] rate was sort of around 7s or 8s for the majority of the innings. They batted really well at the back end and put our bowlers under pressure.
"The bowlers are going to learn, that's all we can ask.
"We're hugely disappointed with the result, naturally. We're here to win games of cricket.
"But we don't have much time to reflect. We're going to be back on the park in a couple of days and hopefully guys can put good what went bad today.
"There were some good things today, and we'll take that forward too."
After Kevin O'Brien's 8th over dismissal, Balbirnie and Stirling put together a partnership of 102.
And the captain says Stirling's innings was easily the standout of a frustrating day.
"He's obviously a world class batsman, and to bat 50 overs and get a score like he did and get us to a total which we thought was just above par on a pretty slow wicket.
"After 141-1, certainly we were looking at maybe 300 and unfortunately I got out, and that sort of gave them a bit of momentum.
"But we managed to take some momentum into the second innings with us too."
That momentum was worn down by the batting of Rizwan and Usman, setting the hosts up for victory.
The sides will meet in the second of four one-day internationals at the same venue on Sunday.
UAE Men v Ireland Men, 1st ODI, Abu Dhabi, 8 January 2021
Ireland 269-5 (50 overs; P Stirling 131*, A Balbirnie 53; R Mustafa 2-43)
UAE 273-4 (49 overs; C Rizwan 109, M Usman 105*; C Campher 2-31, B McCarthy 2-63)
- UAE v Ireland – 2nd ODI – 10 Jan 2021 (start: 9.30am local time / 5.30am Irish time)
- UAE v Ireland – 3rd ODI – 12 Jan 2021 (start: 9.30am local time / 5.30am Irish time)
- UAE v Ireland – 4th ODI – 14 Jan 2021 (start: 9.30am local time / 5.30am Irish time)
- Afghanistan v Ireland – 1st ODI – 21 Jan 2021 (start: 9.30am local time / 5.30am Irish time)
- Afghanistan v Ireland – 2nd ODI – 24 Jan 2021 (start: 9.30am local time / 5.30am Irish time)
- Afghanistan v Ireland – 3rd ODI – 26 Jan 2021 (start: 9.30am local time / 5.30am Irish time)