Hong Kong, who won the toss and chose to bat in the Twenty20 contest, had no answer to Afghan opening pair Shahpoor Zadran and Merwais Ashraf, slumping to 15-6 in the eighth over.
Ashraf (3-8) and Zadran (2-9) polished off the top order in pacey unchanged opening spells of four overs each. Hong Kong was eventually bowled out for 63 in 17.4 overs.
Afghanistan raced to 66-2 in 13.2 overs to secure a place in Thursday's semifinals against Pakistan. Wikcet-keeper Mohammad Shahzad and former Nowroz Mangal both remained unbeaten on 20.
For Hong Kong, Nadeem Ahmed (17) and Jamie Atkinson (16) both fell to captain Mohammad Nabi's offspin bowling.
"I think Pakistan will be more scared of us after today's performance than we are from them," Said Nabi .
Zadran hoped the wicket stays the same on Thursday.
"I think every fast bowler will love to bowl on such a lively track," said Zardan, who struck twice in his third over to reduce Hong Kong to 12 for four.
Afghanistan took wickets at regular intervals and never allowed Hong Kong's batsmen to settle down. as Nabi wrapped up the innings when he had Ahmed stumped.
"I think Afghanistan used the conditions very well," said Hong Kong captain Najeeb Amar, who was run out in the first over without scoring.
Sri Lanka will play Nepal in the later quarterfinals on Wednesday with the winner taking on Bangladesh in the other semis.
Scores in brief
Afghanistan vs Hong Kong at Guanggong International Cricket Stadium
|AFG Won by 8 wickets (with 40 balls remaining)
Man of the match: