If Padraig Harrington is looking for good omens before the Open Championship at Royal Birkdale this week and the defence of a title he won in such dramatic fashion at Carnoustie in 2007, he need look no farther than his victory in the Irish PGA Championship on Saturday.

Last year, Harrington eschewed the big money on offer at the Scottish Open and plumped for something a little more low-key but potentially far more beneficial - the chance to hone his game on a links course.

The European Club in Co Wicklow provided the perfect warm-up for Harrington in 2007. The Irishman came away with a win under his belt and confidence intact, and will be hoping for more of the same after his four-shot victory over Philip Walton on the same course at the weekend - a tournament that he finished with a double bogey, as he had done at Carnoustie before beating Sergio García in a four-hole play-off.

Talking about the challenge ahead, Harrington was determined to keep the pressure to a minimum. “My performance this year at the Open will have no reflection on my performance of 2007,” he said. “There’s no point trying to burden myself with expectations. It doesn’t make any difference. If you turn up and you don’t play well that week, they don’t take it off you.”

At 36, Harrington admits that while he is “hungry” to win another Open, he would first choose one of the other three major championships - the Masters, US Open or PGA Championship. “If you were going to tell me I'm going to win one more major, I'd pick one of the other three,” he said. “And if you're going to tell me I'm going to win three more majors, I would pick all of the other three.”

It is impossible to look back on Carnoustie and not think of the moment when Harrington seemed to have thrown away victory after twice visiting the Barry Burn at the 72nd hole. For one fleeting moment, his body language spoke volumes as he looked up at the giant yellow scoreboard and saw García one shot ahead of him with just the 18th to play.

“You can see that when I turned around and looked at the leaderboard, my whole body sinks,” Harrington said. “When I hit the third shot in the water, I just died. I felt embarrassed. I thought I had choked, had thrown away the Open.”

Those feelings, however, were cut short when Caroline, Harrington's wife, let their three-year-old son, Paddy, run on to the green and into his father's arms. “I suppose he felt like I had won,” Harrington said. “I was a champion in his eyes and I walked off the green feeling that way.”

It was because of this that Harrington remained so positive while waiting to see how García played the final hole. The Spaniard missed a six-foot putt for victory and Harrington says he knew then that the Claret Jug was his for the taking. “I was sitting in the recorder's hut watching his putt, telling myself I was going to win the Open,” he said. “I just knew I was going to win it.”

And when he did go on to lift the most famous trophy in golf, he was heard to promise his son that he “could indeed put ladybirds in it”. So, has he? “Ladybirds have gone in there, yes, definitely,” Harrington said with a twinkle in his eye that suggested it meant more to him than his boy. “It wasn't that he was fussed about it, but I insisted that we had to do it.

“I also have some nice replica ladybirds - stand-up plastic ones - that do sit in the Claret Jug and I had some engraving done with ladybirds going into it [the champion's replica trophy] to remind me of it.”

Perhaps the most unlikely story involves the taxi ride after a night out in San Francisco, where Harrington had been visiting friends and had taken along the Claret Jug in a steel box. Curious that the driver was wearing a golf glove, Harrington got to talking about golf without letting on who he was or what was in the box. “When I got out, my two mates told him that it was the Claret Jug,” he said. “Of course, he didn't believe it. And I'm sure that he still doesn't.”