Australian Jason Day held on firmly to his one-stroke lead in the third round of the Masters on Saturday.
Starting at six under, Day opened with three straight pars to stay ahead although he was briefly joined atop the leaderboard by countryman Marc Leishman.
Leishman, joint second overnight, birdied the second, but dropped one at the fourth to slip back to five under.
Freddie Couples remained at five under through three holes with four players -- Adam Scott, Jason Dufner, Brandt Snedeker and Angel Cabrera -- all on four under after a handful of holes.
Meanwhile, Tiger Woods, hit with a two-stroke penalty for an improper drop before the round started, opened with a birdie and was at two under through seven holes, four strokes off the pace.
South Africa's Tim Clark, Masters runner-up in 2006, set the benchmark early on with a five-under 67, having gone out in 31, to get to three-under par.
Phil Mickelson's hopes were shattered as the three-time former winner slipped out to eight over with a 77, while defending champion Bubba Watson, out first alone, came in with a 70 to get to two over.
Chinese 14-year-old Guan Tianlang struggled to a five-over 77 and at nine over was last but one of the 61 players who made the cut.