Chasing 154 to win, Afghanistan overhauled the target with two overs to spare and knocked Hong Kong out of the tournament in the process as Shafiullah came up with a blistering unbeaten knock of 51 off just 24 balls.
Shahzad, who hit 68 off 53 balls, and Sahfiullah added 47 runs for the third wicket before the opener was caught by Irfan Ahmad off Haseeb Amjad. Shahzad hit nine boundaries in his significant knock.
Shafiullah smashed three sixes off Aizaz and then raised his half-century in the next over with a sweep shot off Haseeb Amjad. The boundary also completed their win.
"I didn't play well in the last two matches so the coach told me to take my time. Everybody supported me in the match. It was a good fifty for me and it was a good win for us. In t20, everything is possible. We need to see the result of the next match and hopefully we can make it to the next round," Man of the match Shahzad said after the victory.
Waqas Barkat (32), skipper Jamie Atkinson (31) and Mark Chapman (38) were the only batsmen who made a mark with the bat.
Hong Kong could manage just 51 runs after losing the top-order batsmen inside 14th over as Shapoor Zadran (2/27), Hamza Hotak (2/32) and Mohammed Nabi (2/27) took two wickets each.