Swing guru Bob Torrance believes Padraig Harrington can complete the career Grand Slam and outgun Tiger Woods down the stretch in a Major.

The grizzled Scot, 75, watched on TV from his home in Largs as he his top pupil grabbed the US PGA and his third Grand Slam title from his last six starts.

And he has no doubt that Harrington would love to go head to head with Woods down the stretch for one of golf’s major prizes.

Torrance said: “He would love to do take on Tiger. He’s done it before anyway, though not in a Major.

“This latest success won’t slow down his work-rate and I now believe he will win all four majors in his career.”

Torrance knows Harrington better than most and watched his No 1 student change his mental approach to become one of the most positive players in the world.

He explained: “Padraig is thinking more positively. He always used to be waiting on bad shots, but he doesn’t do that now.

“When he hits a bad shot, it doesn’t bother him. Some of the shots he hit on the back nine at Oakland Hills were brilliant.

“The one that stood out for me was similar to Carnoustie, his up-and- down at the last. I thought that was superb.

“His eyes looked like a boxer’s about to deliver a knockout blow. I don’t think anything is beyond Padraig.

“He didn’t drive the ball particularly well at Oakland Hills, but he was so determined and dedicated. When you have that kind of attitude, there’s nothing you can’t achieve.”

Torrance has been tipping Harrington to win a Major in the US for several years.

He said: “To be honest, it didn’t surprise me that he won a major in America. Padraig is so dedicated. He just works non-stop and that is the answer to everything.

“It doesn’t matter what walk of life you’re in, whether it’s the sporting or business world, if you work at the right things, you’ll improve.

“This latest success won’t slow down his work-rate and I now believe he will win all four majors in his career.”

Harrington wasn’t Torrance’s sole success in Detroit with Alastair Forsyth sneaking into a share of ninth place with Justin Rose, Jeev Milkha Singh and Charlie Wi.

Torrance beamed: “Brilliant. There’s one thing about Alastair, and it is that he’s not frightened to win.

“He’s a confident young man and, if he gets a sniff, he’ll follow through. He won’t back off.

“This is his best performance in a major without a doubt and I can see him doing more of this, but he has to stop getting down on himself when he hits a bad shot.”