The tournament in the United Arab Emirates determines which teams will qualify for next year’s T-20 World Cup in Australia.
Hong Kong won the toss and elected to bat, scoring 153 in their 20 overs. Kinchit Shah top-scored with 79 off 54 balls.
However, Ireland reached their target with 16 balls to spare, losing only two wickets in the process.
Hong Kong will hope to get their first points of the tournament on Sunday, when they take on Oman.