كتب : Hatem Maher
The in-form striker, who plays for Norwegian side Fredrikstad FK, opened the scoring after eight minutes with a close-range effort following a low cross from lively right-back Samuel Inkoom.
Ransford Osei doubled Ghana's lead on 28 minutes when a precise cross from David Addy found him to slot home from six yards out.
Korea's Park Hee-Seong pulled one back three minutes later with a looping header after capitalizing on a mis-timed jump by Ghana keeper.
Adiyiah restored Ghana's two-goal cushion on 78 minutes after a superb individual effort as he danced his way past several defenders before poking home.
He took his tally to six goals in five matches to lie on top of the scorers' chart.
Kim Dong Sub narrowed the gap once again with eight minutes remaining but Ghana, who reached the tournament's final twice in 1993 and 2001 but finished runners-up on both occasions, held onto their lead to book a last-four berth.
They will face Hungary, who defeated Italy 3-2 in a thrilling game later in the day, in the semi final.