World number one Rory McIlroy was among a quartet of players atop the leaderboard after continuing his sparkling form with an eight-under-par 64 in the first round of the USPGA Tour BMW Championship at Crooked Stick in Carmel. Related Stories Rich pickings for Rory McIlroy Rory McIlroy could raise bar to new level Rory McIlroy can't get enough awards McIlroy shares lead in Carmel