Links Championship: Paul Casey signalled his determination to win the Order of Merit in style with a brilliant first round in the Alfred Dunhill Links Championship in Scotland yesterday.

Casey carded a nine-under-par 63 at Kingsbarns - one of the three courses used for the pro-am event - to lead by one shot from Wales' Bradley Dredge and Sweden's Johan Edfors, two better than Vijay Singh and three ahead of Ireland's Padraig Harrington.

Casey, who could clinch the Order of Merit this week with a victory and suitable performances elsewhere, insisted he was keeping the issue at the back of his mind.

"I'm really not going to think about it," said the 29-year-old, who overtook David Howell by winning the World Matchplay at Wentworth the week before the Ryder Cup.

"I would dearly love to win it and if it happens, it happens, but if it doesn't, it doesn't.

"But it would be a wonderful honour. I have achieved so many of my goals this year and feel very satisfied so, if I was to win, it would be brilliant. If not, then it doesn't matter as I've had a wonderful year anyway.

"I can't control what the other guys do. I have David behind me and a few other guys are very much in it.

"Padraig Harrington asked me this morning if I was playing in Mallorca before Valderrama but I'm not going to change my schedule. I am tired and I need a break."

Casey, who carded seven birdies and holed out from 80 yards on the sixth for an eagle, could only finish 56th out of 62 last week as the World Matchplay and Ryder Cup took its toll.

"That's all it was and I couldn't control that," added Casey, who recorded only the fifth hole-in-one in Ryder Cup history at The K Club.

"I still feel tired but I went into today with a really good attitude and didn't expect too much. That's what I intend to do for the rest of the week. I'm not going to change the whole routine and go all serious just because I'm in front."

Casey is currently €120,000 ahead of Howell and €372,000 clear of Robert Karlsson, but the vast amounts of prize-money on offer here and in the season-ending Volvo Masters at Valderrama means Karlsson (third), Henrik Stenson (fourth), Harrington (fifth) and Colin Montgomerie (seventh) are among those still in with a chance of topping the standings.

Harrington was the best placed of those after an opening 66 while Karlsson and Stenson both returned rounds of 68. Montgomerie - seeking a ninth Order of Merit title - could only manage a 73.

Harrington, starting at the 10th, birdied his first four holes and added a fifth at the 565 yards 16th to be out in 32. Two more birdies on the homeward run saw him back in 34 to be well in the hunt for the top prize of €630,566.

Dredge's 64 at St Andrews established a new course record for the lengthened layout and could have been significantly better but for a double-bogey six on the 17th where he drove out of bounds.

Still, for all the heroics of Casey and the others at Kingsbarns and St Andrews, the real leader at this early stage may well be Anders Hansen. The Dane shot 30 on the back nine and made a remarkable seven birdies en route to a six-under 65 at Carnoustie, easily the toughest of the three courses of this celebrity pro-am event.

Graeme McDowell and Damien McGrane on 70 are the next best of the Irish. Peter Lawrie and Paul McGinley are on 71 with Michael Hoey and Gary Murphy on 72, while Darren Clarke shot 76.

• Guardian Service