Patience and courage characterised the Irish challenge here. While comfortably making the cut, Darren Clarke and Padraig Harrington both survived mid-round crises to break par, with the Dubliner gaining the distinction of a brilliant 69.

It was an especially creditable effort by Harrington on his debut in this great event. From a position of four-under-par for the round on the ninth tee, he had slipped back to level by the 12th. But from there, he covered the remaining holes in three under, finishing with a sparkling birdie on the 18th.

"The really crucial thing was to par the 12th," he said afterwards. "I knew I would have birdie chances at the par fives and I'm obviously delighted with the way things have worked out."

He added: "After today, I no longer have any doubts. This is one of my favourite courses, mainly because of the demands it makes on every aspect of your game. It's a real treat to have made the cut and I was particularly pleased to have holed that last putt for a 69."

After a 76 on Thursday, Harrington was under considerable pressure. So it was clearly a boost to birdie the first from 20 feet and he later birdied the sixth (25 foot putt), seventh (15 feet) and long eighth, which he reached with a four-wood second shot. Then came the set-back of a double-bogey six at the ninth, where a serious miscalculation saw his seven-iron second scamper through the green.

His closing birdie was a delightful effort. From a perfect drive faded off the fairway bunkers, he hit a 100-yard L-wedge downwind to 10 feet right of the pin. And he read the right-to-left break perfectly to find the target.

Meanwhile, with seven birdies on the card, 71 seemed a decidedly modest return for Clarke. But the World Matchplay champion is swinging so confidently right now that he believes there are many more birdies to follow.

In a way, this was vintage Clarke, for whom momentum is the breath of golfing life. It explains how he has twice shot 60 on the European Tour and why he could make two closing birdies for a 72 on Thursday. On this occasion, the streak involved four successive birdies from the 13th.

His form over the first six holes, which he covered in three under par, was as good as anything he produced at La Costa in February. And at three under par for the championship at that stage, he had a clear chance of being among the half-way leaders.

"For some reason, the momentum deserted me at the seventh," he said. "I lost my way a bit and the result was a topsy-turvy round; an eventful day." Then he added: "But any time you break par around here, you've done well. So I can't be disappointed."

The errors from the seventh to the 11th, cost him five strokes. But when he sank a priceless return putt of eight feet for a par at the short 12th, his confidence returned. "Billy settled me down," he said, referring to his caddie, Billy Foster.

"Walking towards the 13th tee, he urged me to make a few birdies and get back into the championship. His overall contribution was huge, not least in the number of shots he saved me." The result was a stunning run of four birdies in a row, from the 13th to the 16th.

The run created such a sweet feeling, as to take much of the edge off a closing bogey. And so, the weekend beckoned.