gary ballance is now averaging in excess of 60 for england .
ballance 's knock of 122 was impressive at no 3 .
joe root shone before he was eventually dismissed for 59 .
jos buttler also did well with the bat , an unbeaten 59 off 56 balls .
stuart broad struck early , clean bowling out kraigg braithwaite .
england finished the day eight wickets from victory in first test .