While meeting with Michael Bonallack at a function in Carnoustie last week, memories of my greatest moments in golf came flooding back. It was St Andrews 1971 and he was playing-captain of the Walker Cup team in which I had the good fortune to set a record with three and a half points out of four.

All of my matches went to the 18th but two of them really stand out. The first was on the opening day in the second foursomes with Charlie Green, who would probably have been more at home with my father given that they played umpteen times together. But, from my standpoint, it was a master-stroke by the captain.

I also had the advantage of a wonderful caddie in Tip Anderson - you just reached out and the correct club was placed in your hand like a surgeon's scalpel. I threw my yardage book away after the first day.

Anyway, against Steve Melnyk and Vinny Giles, I kept leaving Charlie with three and four-foot return putts. But, on the 18th, he ran me two and a half feet past - the exact putt that Doug Sanders had missed for the British Open at St Andrews a year previously.

I'm looking down behind this and I'm thinking it's left lip. But Tip said it was right half. Then I looked him straight in the eyes and demanded: "Are you absolutely sure?" In a situation like that most caddies would back off and agree with the player, but Tip insisted it was a firm putt on the right side. So I yipped it right, and it went in.

The other memorable 18th situation was on the final afternoon, which provided the most magical moment of all. I was playing Jim Simons and it was a long day which included a warning for slow play. But it seemed to be ending just fine for me when, one up on the last, I hit a wedge second shot well up the green.

The pin was in the classic "Sunday" position, just over the Valley of Sin and Simons, a terrific putter, was eight feet away in two. There were 10,000 people around the green. And Pop, who was smoking at the time, was hidden among them somewhere. Earlier, out on the course, I had seen the puffs of smoke wafting up from behind bushes: our agreement was that he could watch me provided I couldn't see him.

Anyway, I knelt down behind the putt to study its line - and I said a Hail Mary. "Please Jesus, let me get it close," I prayed. This was more pressure than I had ever known. It was 11 yards and Tip gently urged me to give it a nice, smooth roll down towards the hole.

At that moment, I remember my mother's advice to do it the Harry Bradshaw way, which was hit and hark; don't move your head.

I was conscious of an amazing silence as I hit the ball. Then, after what seemed about five seconds, I looked up and thought `Oh no, it's only going to go halfway to the hole.' It was so silent I could almost hear the crowd breathing.

The ball kept going. I couldn't see the hole because they didn't paint the inside of the cup in those days. And still it rolled. Eventually, I knew it was going to get close enough to be dead. So, I'd done my job. If Simons sank his, at least I had put him under sufficient pressure.

Suddenly, my ball appeared to stop on the lip of the hole. Then it fell in. And still, there was silence. It could have lasted no more than another split second before the crowd erupted, sending a shiver right through my body, from head to foot. It was some time before I realised it was all over: I had taken him out.

Next thing I remember was J B running out from the crowd and giving me a big hug. It wasn't his style to be demonstrative but now, as a father myself, I realise what a thrill it must have been for him. Though he had performed similar exploits many times himself, the buzz he got from watching his son must have been amazing.

Meanwhile, Warren Humphreys was sinking rakers to bury Melnyk and David Marsh was hitting the shot of a lifetime, a three-iron onto the 17th as he headed for victory over Bill Hyndman. In fact the roar which greeted David's shot, came just as I was preparing to putt.

A picture of the triumphant moment on the 18th, remains my prized possession, with my hands in the air and Tip in the background. Looking at Michael Bonallack the other night and remembering our 13-11 win, I thought of how much I owed him for picking me as a flier and playing me in all four matches. And for giving me the most thrilling moment of my life.