Tiger Woods is charging up the Masters leaderboard Saturday afternoon, but Brandt Snedeker is playing well enough to keep a comfortable cushion on the world's best golfer.

Woods was 4-under for the day and 5-under for the tournament through the 17th hole of his third round at the Augusta National Golf Club. He trails Snedeker by four shots.

Snedeker entered the day one shot behind second-round leader Trevor Immelman. Snedeker posted a 2-under 34 on Augusta's first nine to get to 9-under for the tournament.

Immelman is a shot back after playing an ever-par first nine. He bogeyed the par-3 fourth hole but reclaimed that stroke with a birdie at the par-5 eighth.

Paul Casey and Steve Flesch are two shots off the lead. Casey shot a 4-under 32 on the first nine to briefly tie Snedeker for the lead at 8-under. But Snedeker made a birdie at No. 8 and Casey bogeyed the par-4 11th hole to fall back.

While Woods and Casey moved up, two-time Masters winner Phil Mickelson slipped down the leaderboard. Mickelson was 2-over par through 10 holes and tied for eighth at 3-under for the tourney.