Colin Montgomerie delighted the enthusiastic galleries with a spirited round of 70 that left him at nine under, three shots behind Tiger Woods.
Given a rousing reception in the final group with Woods, he parred the first four holes, then birdied the fifth.
Successive birdies came from the ninth before he three-putted the short 11th.
His approach to the 17th found an awful spot in the bunker and he did well to make a bogey, but a 12-foot putt on the last toppled in to keep him in touch.
Montgomerie began the day four shots behind leader Woods and pulled a shot back when the American three-putted the second and by the 10th there was just one shot in it.
The home favourite had reclaimed another shot when Woods suffered a penalty drop at the sixth and although the 2000 champion picked up a shot at the next, Montgomerie picked up a birdie at the ninth to stay in touch.
One hole later the lead was down to one as the Scot sunk a birdie putt to the delight of the crowd.
But two putts on the 11th saw Monty drop a shot and Woods collected another at the 12th while the Road Hole bunker also cost Montgomerie a stroke before his thrilling final hole birdie.
Montgomerie's third round 70 was a shot better than Woods and he is brimming with confidence for the final round.
Montgomerie and his fans celebrate his birdie at the 18th
"I can win this," he insisted.
"If I can shoot 66 I have got every chance. There are a number of players who know they can win.
"I have an opportunity to win a major and I must not leave any putts short."
Montgomerie was overwhelmed by the level of support he received from the packed galleries.
"No words can describe the crowd. It's lovely to feel the warmth of support. It's so exciting - it's our major sport and this is a very special place.
"There were 15 grandstands out there and I had a standing ovation on every
one. It was quite unbelievable and I think they helped the ball in at the last
because I thought I might have left it short again."