Francesco Molinari extended his lead to three strokes at the Masters by again keeping a bogey off his card over the opening holes at Augusta.
Molinari's only bogey through 59 holes this week came at the 11th in round one and he began Sunday with five successive pars to remain clear of the field at 13 under.
His lead, which stood at two strokes overnight, was enhanced when nearest rivals Tony Finau and Tiger Woods both bogeyed the fifth, where Molinari rescued par after a wild tee shot.
Woods had reduced his deficit to one with a birdie at the third.
However, he then bogeyed each of the next two holes, dropping a shot at the fifth for the fourth day in succession despite hitting the fairway with his drive.
Brooks Koepka briefly moved to 11 under with a birdie at the second, but he was alongside Woods and Finau - three of the pace - when he gave that shot back on the sixth.
Patrick Cantlay and Ian Poulter were a shot further back, on a day when tee times had been brought forward by several hours due to the anticipated arrival of thunderstorms in the afternoon.