Riverside charged into O’Neill April 17 and rode home with the St. Mary’s Invitational boys championship hardware and a bevy of individual medals from both boys and girls competition.The Chargers scored 143.5 points to run away with the boys championship, finishing 50 points ahead of runnerup Plainview. Riverside (69.5) placed fourth in the girls division won by Plainview (125).Charger standout…