The fist pumps were back and so were the profanities he had sworn off as Tiger Woods showed both sides of his game and personality in a combative third round at the US Masters on Saturday.

Fans saw the good and bad in a Jekyll-and-Hyde display by Woods as he returned a second successive two-under 70 to sit four shots behind leader Lee Westwood of Britain going into Sunday's final round.

Playing his first event since admitting to a string of extra-marital affairs that drove him into hiding for nearly five months, Woods had been on his best behaviour since arriving at Augusta as he launched a major charm offensive in an effort to win back fans and sponsors.

Woods had pledged during an interview on Monday to give fans and the game more respect and try to tone down his anger and occasional profanity-laced outbursts.

But the 34-year-old American suffered a relapse early on in his third round, letting loose a string of profanities after his tee shot on the sixth hole failed to go were he had wanted.

Questioned about the outburst, Woods told reporters he was not aware of any swearing - which was caught on television - before offering an insincere apology.

"Did I?" deadpanned Woods. "If I did, then I'm sorry."

Woods certainly struggled to maintain the more even-keeled philosophy he said he would try to adopt as he rebuilds his career, enduring a roller-coaster third round that included seven birdies and five bogeys.

The four-time Masters champion was all smiles as his round began, two monster birdie putts at the first and third holes being followed by two of his trademark monster fist pumps.

But when his round began to unravel with a wayward tee shot on the par-three sixth, Woods unleashed a torrent of expletives.

Woods battled to regain his composure and his rhythm falling seven shots off the lead before getting back on track with three successive birdies from the 13th.

The 14-time major winner had another birdie to close his round before walking off the 18th green to wild cheers with a big smile across his face.

Woods later admitted it was a struggle to maintain his composure particularly with "three-putting every other hole".

"After what's transpired, to have that support out there is fantastic," said Woods. "I just wanted to put myself in contention, and I did that.

"After struggling just to fight back in the ballgame, the guys were running away from me there. At one point I was seven back.

"So to kind of claw my way back in there where I'm only four back right now, I'm in good shape (and) a good round tomorrow, you never know."