Corner Canyon (Utah) High stole the high school football headlines on Thursday night, as the No. 11 Chargers defeated No. 9 IMG Academy (Fla.) in a 35-34 thriller, planting its flag on the map of high school powerhouses in the process. The victory snapped an 18-game winning streak for IMG. Heading the attack under center for Corner Canyon was junior quarterback Helaman Casuga, who threw for 330 yards and four touchdowns. Three of those scores went to star wide receiver Jerome Myles — one of the top uncommitted senior prospects in the nation. The touted IMG defense was no match for Myles’ combi…