AUGUSTA, Georgia (Reuters) - South Africa's Trevor Immelman cruised towards his first major title by moving five shots clear with three holes remaining in Sunday's final round of the U.S. Masters.

Keeping his composure in difficult, swirling winds at Augusta National, the 28-year-old was one over for the day and 10 under overall as his closest challengers fell by the wayside.

Aiming to become the first South African to win a green jacket in 30 years, Immelman struck a wedge approach to three feet at the par-five 13th to set up a tap-in birdie and tighten his grip.

That put him five ahead before American left-hander Steve Flesch bogeyed the 15th and 16th to slide back to three under.

Immelman parred the next two holes for his lead to be trimmed back to five when playing partner Brandt Snedeker birdied the par-five 15th.

World number one Tiger Woods and fellow American Stewart Cink were a further stroke back in a tie for third.

Woods, a four times champion at Augusta and the overwhelming favourite at the start of the week, struggled to make headway in his bid for a 14th major title.

Six strokes off the pace going into the final round, he mixed three bogeys and two birdies with just one hole remaining. Cink, level for the round, also had one to play.

BRIEFLY CAUGHT

Two ahead of the chasing pack overnight, Immelman was briefly caught by playing partner Snedeker after the first two holes.

Both players bogeyed the par-four first after failing to reach the green in two before the mop-haired Snedeker rolled in a 40-footer to eagle the par-five second.

Immelman, aiming to become the first South African to win the Masters since Gary Player in 1978, parred the hole after failing to get up and down from the right greenside bunker for birdie.

Although Immelman birdied the par-four fifth after hitting a superb approach to four feet, he squandered an opportunity to forge five ahead when he narrowly missed a three-foot birdie putt at the seventh.

The dapper South African dropped another shot at the par-five eighth where he was bunkered off the tee before three-putting from long range, but did well to save par at the ninth with an up-and-down from the left greenside bunker.

Out in one-over-par 37, he offset a bogey at the treacherous 12th with his birdie at the 13th to stay well ahead of his challengers.

(Editing by Miles Evans)