HILTON HEAD, United States (AFP) — Rory Sabbatini battled through the discomfort of a sore back to shoot a seven-under 64 for first-round lead at the RBC Heritage, with world number one Dustin Johnson not far behind. South Africa’s Sabbatini has a two-stroke lead over a group of four Americans at five-under 66, including Matt Kuchar and Billy Horschel, while Johnson fashioned four consecutive birdies at one stage of his opening round for a 69. […]