HILTON HEAD ISLAND, S.C. – Webb Simpson managed only one birdie on the back nine Saturday at Harbour Town, and that was just enough for him to post a 3-under 68 and join a four-way share of the lead at the RBC Heritage.It sets up another Sunday of endless possibilities on the PGA Tour.Tyrrell Hatton of England had one of six rounds at 63 as he tries to win back-to-back starts for the second time in his year.