A third-round four-under par 68 from Tiger Woods has kept alive both his hopes of a fifth Masters title and a 2008 grand slam.

The world number one moved onto a five-under-par total at Augusta after scoring his first sub-70 score at the Masters since the third round in 2005.

"I put myself right back in the tournament. I'm right there," said Woods, who had four birdies in his first blemish-free round of the week.

Woods started the day seven shots off the lead, and birdies at the second, 10th, 13th and 17th holes saw him slowly build momentum.

He also kept his card clean on the 18th where, as on Friday, he fired his drive into trees right of the fairway.

However, Woods aimed succsssfully through a four-foot-wide gap in the trees before sinking a difficult six-foot putt.

"I just had to fit it," Woods said of his approach shot. "I had 180 to the hole, I had to hit the right trajectory, right line.

"It's either a four or a six. Might as well make four."

Work to do

Woods still has plenty of work to do if he is to claim a fifth Green Jacket - leader Trevor Immelman six strokes ahead after shooting a 69.

And the 32-year-old also has to overcome the statistic of all 13 of his majors being earned when he held at least a share of the lead entering the final round.

"I've got a lot of work to do tomorrow," Woods continued. "Conditions are supposed to be pretty blustery, cooler. It doesn't take much to make a high number out there."

Woods also said he was happy with his game, despite the difficulties players faced on Saturday reading greens softened slightly by a storm that halted play early on.

"I hit the ball well all day," he said. "I hit a lot of putts that didn't have quite the right speed or right line."

Blistering

Having played a blistering approach with a three wood, he two-putted from 20 feet for birdie at the par-five second, with his birdie at 17 being little more than a tap in after he almost holed his second shot.

"I could read that one," Woods added.

"I only made one putt really, the putt I made at 10. Otherwise I didn't make any putts for birdie, they were two-putt birdies or tap-ins.

"A lot of putts were going right over the edge."