Jamabo is ranked as one of the top football recruits in the nation and has committed to the UCLA grid program. But he showed basketball speed with nine early points, including three slam dunks, as Plano West (32-2) built a 17-0 over the first 3:48.
MacArthur (27-9) out-scored the Wolves 69-61 over the rest of the game but was unable to get closer than 74-69 in the final minute.
Three other Wolves joined the double-digit scoring as 19 points and nine rebounds by D. J. Hogg and 18 points and seven rebounds by fellow 6-foot-8 guard Mickey Mitchell was joined by 13 points and nine rebounds by 6-10 post Tyler Davis.
Andrew Jones led MacArthur with 18 points, while Donny Belcher III and Demetrick Bush added 17 points each.