US Open champion Justin Rose led the way at the PGA Grand Slam at Port Royal today, firing a four-under-par 67 and leaving the rest of the field to play catch-up when the second and final round begins tomorrow.His closest rival is PGA Champion Jason Dufner who returned a two-under par 69 followed by Masters winner Adam Scott who dropped three strokes in the last five holes to finish with a one-under 70.Defending champion Padraig Harrington is virtually out of contention — he admitted it would take a miracle to retain his title — after struggling to a three-under-par 74.