The road less travelled. Many years ago Padraig Harrington was a Gaelic footballer. The last serious game he played was in Croke Park. He was centre back and marking a fair-headed young fella and he sprained his wrist chasing after him in the first minute. He got the run around all day and went off to play golf that weekend keeping his mouth shut about the wrist because he knew this was his sport from there on.

Yesterday Padraig was in Southern Hills playing the last round of the US Open with Tiger Woods. And the fairhaired young lad? Dessie Farrell was in Croke Park. You do what you do best.

So how did it feel to be Padraig Harrington yesterday at this particular stage of the journey. Sunday at the US Open. Walking from the practice green to the first tee parting an ocean of humanity.

Everyone is whooping. Three yards behind Padraig Harrington is Tiger Woods wearing the claret red shirt he wears for final day play. All this goes into Padraig Harrington's data bank of experiences.

"I was delighted to be playing with him. It's a good situation to familiarise yourself with. It's like playing the last day when you are in contention. There is so much attention."

Cutting through the crowd, Harrington has a kilowatt grin on his face. All that hollering.

"Just for me?" he says to Dave McNeilly his caddy.

On the first tee it's handshakes and best wishes. Woods and Harrington played against each other in company at the Ryder Cup in Brookline but this time there is a sense of tension which wasn't present even then. Southern Hills country club and most of the people therein genuinely expect that Tiger Woods could pull back a nine-shot deficit.

Padraig Harrington is an extra in this production, but a key extra.

"Ladies and gentlemen this is the 12.45 tee-time. From Dublin, Ireland Paw-Drag Hairington!"

He steps up in a talc-coloured short and slacks and whacks an iron shot into the blue yonder, looking as relaxed as he might for a Sunday morning foursome in Stackstown. He scarcely looks at Tiger Woods' drive.

"Lucky enough with Tiger you aren't in a competition." he says later. "It's not like you are trying to out-drive him. He's playing his game. You play yours.

Most of the time he's using different clubs. There's no sense of competition. He started on the first with a wood, which is tough, and by the back nine I was sort of wandering off on my own anyway."

Still, down the first fairway they walk shoulder to shoulder, slipping into chat to soothe the nerves. Harrington asks Woods if he's coming to Ireland for fishing. Woods says he's going to Alaska.

They part. Harrington's ball has found the first light cut of rough. Woods is better placed. Time to step back and let the Tiger Woods show begin.

At this exalted level you need a fine instrument to calibrate the difference between success and relative failure, between genius and hard luck. It's a couple of lipped birdie putts, it's a bad bounce or a tough lie.

"Not again," Harrington mutters on the second, as he finds light rough again. He and Woods have parred the first and are hitting their drives about equidistant now. Yet it is Tiger who bogeys the second, nerves making him prodigal.

So little separates the best player in the world from his pursuers. On the third Harrington hits a second to six feet. Woods hits his second to 25 feet. They walk away with a pair of pars. On the fourth Harrington has a god-like moment. Leaves his drive on the right, finds the bunker with his second, makes a wonder shot with his third and putts sweetly for regulation.

"Nice par," Tiger Woods says. Then he drops his birdie putt into the hole. It's that way right to the turn. Respectful jousting. Tiger is playing with the greater ambition. He believes he can contend. Harrington is playing with the greater patience, he knows he can consolidate and build and learn but never believes he can get to three under, which he believes would be a contending score.

Then, on the turn, they go their separate ways, Harrington down the fork of the road for ordinary but talented mortals. Woods the other way, walking on water. An array of small setbacks pins Padraig to the ground. He bogeys the ninth and bogeys the next three holes and his face tightens. He knows he is a better player than the one this gallery is seeing now.

"I struggled with my concentration really. My tee shot on nine, got the wind a little wrong. Bunker. I hit seven or eight bunkers in nine holes. Tenth? Seven iron and pulled it. Bunker. Eleven, playing to middle of green. Eye on pin and pulled it left and missed green. Twelve, down the middle going to middle of green with one eye on pin. Hit it fat to bunker. Fifteen, three wood from bunker. Sixteen, kicked left into bunker, chipped out again. Everytime I'm in there I'm chipping out and it's a straight bogey."

Six bogeys in the last 10 holes. Not his A game. Not his B game. He adds the experience to the aggregate of all his experiences. They come to the 18th, both smiling, in the brilliant sun. Harrington surveys their shots balefully, says to the greatest player in the world, well thanks be to God they didn't cut the grass on 18 or we'd both be 50 yards off. Tiger laughs.

You said it.

And they suck in the applause. Tiger is hustled off with four policemen stuck to him. Harrington strolls towards the clubhouse and the little gaggle of media who want to hear about his day.

"My day? Well it could happen again when something is at stake and I wouldn't be so accepting of being five over on the back nine. I've familiarised myself with a situation that I hope will happen again in better circumstances. I have the experience. Next time I play with Tiger Woods I won't have seven media guys asking what I learned."

And for Tiger Woods? He has seen that Tom Kite and Vijay Singh have already had the sort of round he was intending for himself. Some guys he couldn't pick out of a police line-up are jousting for his title but some invisible barrier of form or fortune has kept Woods from the low 60s. Ah well! One of those days, just one of those days.

One that Padraig Harrington will be nourished by. A Sunday at the US Open. Tiger Woods and half the world for company. A serious challenge for a serious player.