Padraig Harrington plunged dramatically from skilled craftsman to fumbling duffer in a remarkable 65, which left him within a stroke of the lead at the halfway stage of the £1 million Volvo Masters at Montecastillo yesterday. While the Dubliner carded 11 birdies for the first time in his career, Retief Goosen retained the lead on 130 - 14-under-par.

Welcome sunshine began to dry the sodden course and a testing breeze freshened during the afternoon, when Harrington was in action. Yet the scoring remained of a stunning quality, to the extent that only six players from the field of 66 are over par. Almost predictably, there was a surge from Order of Merit leader Colin Montgomerie, who moved menacingly into a share of third place on nine under par, after a bogey-free 65 which he completed with three successive birdies. "Those people out there who were hoping I was going to have a quiet week, don't know me well enough," he said with a thin smile.

The big Scot sank putts of 25 feet, 10 feet and eight feet for birdies at the 16th, 17th and 18th to lift what had otherwise been a moderate round by his standards. It represented a significant lift on his form of the previous day when he struggled with a migraine headache.

Montgomerie's determination to remain at the top of his craft, is reflected in an intriguing, equipment decision this year. Unlike most players who fiddle around with lofts and lies through trial and error on the practice ground, he has had his 10 irons made with a precisely uniform gap of 4.4 degrees in loft between each club - 44 degrees in all. All with a view towards achieving greater consistency.

In the event, Harrington wasn't the only player producing spectacle. The Spaniard, Francisco Cea, found a decidedly rapid route to an outward 32 when holing an uphill, three-wood second shot of 221 yards for an albatross two at the 517-yard ninth. In sharp contrast, Goosen was admirably solid in a 68 which contained five birdies and a lone bogey at the difficult 15th.

Meanwhile, Paul McGinley failed to achieve the necessary return from what he described as the most important club in the bag, in the prevailing conditions. But an eight-footer and a 30-footer still managed to find the target in a back nine of 32 for a round of 71 which got him into the red.

Darren Clarke shot an undistinguished 70 to maintain a solid defence of the title. His hopes of anything better were greatly diminished by the fact that he was fighting a hook for much of the round and was level par with two holes to play.

Then came the sort of finish guaranteed to add a special tang to an evening meal. With a wedge to 10 feet he birdied the 17th and he also birdied the last, holing a 15 footer from precariously close to the water's edge. "Mediocrity at his finest," was how he described his day's work.

There could hardly have been a more inappropriate epithet to describe Harrington's effort. It positively bristled with excitement, from the time he swept to nine under par for the tournament through birdies at the first three holes. They were the products of two 12-foot putts and a two-footer at the long third.

And his progress up the leaderboard was further enhanced by birdies at the fifth, where he sank a six-footer and at the sixth, where he had the good fortune to hole a 30-foot chip from off the left side of the green. Goosen, four two-balls behind him in the last pairing of the day, now saw his lead seriously under threat.

That was when Harrington produced his first serious error of the round, by blocking a seven-iron approach into water on the seventh to run up a double-bogey six. But he partially recovered with a two-putt birdie at the long ninth for an outward 32.

The homeward journey was similarly eventful. A 35-foot putt yielded a birdie at the 10th; he chipped dead for another at the long 12th and sank a 20-footer at the 13th. But as if preferring the rocky route, he found trouble once more at the difficult, 464-yard 15th.

From a moderate drive into rough, Harrington attempted a three-wood recovery - and hit the ball all of 15 yards. "I topped it; lifted my head; almost missed the ball altogether," he admitted afterwards with admirable candour. "I suppose I could protest that the lie wasn't ideal but there's no point. It was a terrible shot."

Then came another bogey at the treacherous 17th, where he had dropped two strokes the previous day. Again he was in the water, this time off his drive - "I should have taken the three wood off the tee instead of the driver." But again he found the necessary concentration and determination to make good the damage, which he did by sinking an 18-footer for a birdie on the last.

All of which meant that along with 11 birdies, he had two bogeys, a double-bogey and only four pars. Yet it wasn't the most eventful round of his professional career: that happened on the final day of the Lancome Tournament in 1996, when a sparkling 62 included three holed chips.

"I hit a lot of good shots today, so I have to be pleased, but I don't know how I'm going to play tomorrow," he said afterwards. He then had the good grace to feign embarrassment when adding: "I got a few putts." Indeed he did. In fact the blade was working so well that he needed it only 24 times. Added to his 28 putts on Thursday, this represented a very good return indeed.

But he knows that on current form, Goosen will be difficult to catch. "The wind started blowing very strong on the third hole and from there, I played very solid," said the South African, who had two birdies in the bag by that stage. "Some of the guys had very good rounds today but I'm trying to keep my nose in front."

Harrington made a point of mentioning that he liked Montgomerie's position. But the Scot was four strokes behind him, he was told. "Yes, I know. But he's nearly £800,000 ahead of me in the Order of Merit." After a momentary lapse to duffer's standards, he was thinking like a professional again.