The England captain blazed 154 not out set his side up for a comfortable 189-run win over the national age-group side in St Kitts.
The Hampshire batter hit 13 fours and four sixes in his 119-ball stay, as his side posted an imposing 362 for six.
Only Dan Lawrence, who was an unused squad member during England senior team’s Ashes debacle this winter, has made a higher individual total for England’s U19s in 50-over cricket.
Faced with such a daunting chase, UAE were reeling immediately as they fell to 61-5 in the 15th over.
For the second match in a row, Ali Naseer made a counter-attacking half-century. The Dubai-based all-rounder hit 54 from 44 balls to help salvage some pride for UAE.
He put on 59 with fellow ICC Academy student Nilansh Keswani, but once the latter departed, the last four wickets fell for 53 runs.
Leg-spinner Rehan Ahmed was the pick of the England bowlers, with 4-30 from his 10 overs.
England dismissed the UAE for 173 to confirm their place as group winners, and they advance to the Super League quarter-finals.
UAE still have a chance to join them. They face defending champions Bangladesh on Saturday in the final pool game, with the winners set to advance.