New Zealand skipper Kane Williamson, who normally appears as a serious fellow, was at his wittiest best on Thursday when he asked Sri Lanka's Angelo Mathews about his helmet strap the moment he reached at the crease to take the strike in the World Cup match at the Chinnaswamy Stadium in Bengaluru. New Zealand opted to field first, a decision that was supported by their bowlers as they consistently took wickets, despite an aggressive 51-run contribution by Kusal Perera for Sri Lanka.