Greg Norman birdied three of the last four holes to halve Craig Stadler's commanding four-stroke lead in the Senior British Open over Royal Aberdeen's Balgownie links yesterday.

Norman, making his debut on the over-50s circuit, came surging up through the field in the evening with a four-under-par 67 - the best score of the wind-blown tournament so far.

Playing amazingly well for a man who had major back surgery a little over four months ago, Norman moved to one over par at halfway and stopped Stadler from threatening to make it a one-horse race over the weekend.

"The difference today was that we just got used to the wind. It wasn't as gusty and strong as it was yesterday, but it was still up there around 20-25mph but I got to know the golf course, got to know the lines where you've got to hit it," said the Australian.

"I hit a lot more good shots too, which is helpful. Controlling the distance is crucial around here and just staying patient is also very important."

Norman shot seven birdies in all, holing from 15 feet for a two at the short 17th and 30 feet across the last green, having also carded three bogeys.

Stadler was pleased with his day's work of 68 in blustery conditions which did not quite match the 30mph gusts of Thursday, when he shot a 73.

"Today was very satisfying. I hung in there. I took advantage of my opportunities to make birdies. Four birdies and a bogey around here are pretty good," he said.

"I still will not say that I hit the ball perfectly, because I didn't. Far from it. But I just kept it in play and was patient and pretty much got as much as I could out of it.

"It's very easy to walk off the 18th green and look at your card and think, well, there's four or five I saved. And that's the way to play around here when the wind blows."

That last comment referred to up-and-down saves at the par-four 10th and 18th, plus the short 17th.

"I'm still playing the par threes horribly. I think I've hit two greens out of eight so far," added Stadler, whose triumph at the 1982 Masters was the pick of his 13 titles on the USA PGA Tour.

Another Major champion, American Tom Watson, moved up to tied-fourth on the leaderboard after a level-par round of 71 that featured four birdies, while alone in third is Ireland's Des Smyth.

Smyth reversed his round from Thursday, when he struggled on the front nine, to reach the turn in 34 after a stunning eagle three on the 554-yard second hole.

"I hit drive, five wood and I had a mid-wedge 75 yards into the wind and one bounce and straight in. That was exciting," said the 52-year-old from Drogheda, who dropped three shots coming home to finish with a one-over-par 72 and a two-round total of 145. Next best of the Irish is Mark McNulty who shot 72 to leave him on 148.

A stroke further back on Smyth are Watson, Argentina's Eduardo Romero, overnight leader Loren Roberts of the USA and Italian Giuseppe Cali.

Scotland's leading player is John Chillas, who birdied the last to finish with a 74 and a share of 13th place with England's Mark James, American Alan Tapie and South African Bobby Lincoln, who are all on 149.

A total of 79 players 15 over par or better made the cut but those who missed out included one of the pre-tournament favourites, Tom Kite, after an 83 and 77, and defending champion Pete Oakley, who finished 20 over after a second-round 80.