Moody Monty swore and was rude to reporters yesterday, but was a changed man when he faced the press this afternoon, laughing and joking all the way and answering questions far more courteously.

After fearing he had done too much damage to his hopes of a first major with that three-over-par 74, Montgomerie revealed his overnight changes which made all the difference, and which bolstered his belief that he can claim the Claret Jug on home soil.

He said: ‘‘I changed my clubs last night, I went to the car and found another set and thought: ’Oh bugger, I’ll put them in’. They worked.

‘‘I saw myself on a big screen as I drove to the Open advertising a club I have never used before, the Big Bertha iron, and thought: ’That’s me, oh God’, so I got them to make up a set for me on Tuesday and I used them today.

‘‘The most important thing after a disappointing 74 was that I couldn’t afford to drop a shot, and I didn't. That means everything seems to be in order, the driving, chipping and putting, so that augurs well for the weekend.

‘‘I was glad I was playing early/late because I didn’t have time to dwell on a 74. I just had room service last night, had a good think and went out this morning slightly more aggressive.

‘‘I wanted to prove to myself that I can still do this and compete at this level, and I did that today. A 64 around here is a good score, without dropping a shot and if I can keep doing that I have a chance here.

‘‘I want to keep this momentum going. I know I can win. I have never been frightened of winning. I’ve got to use that psychology in a positive way over the weekend.’’

Montgomerie attacked from the off and made the perfect start with a birdie at the first hole. He followed it up with an eagle at five and birdie at six, and picked up further birdies at nine and 15 before ending on a high with a birdie at 18.

‘‘This ranks up there with the first day of last year’s Open,’’ he added. ‘‘This is my lowest score in an Open - I’ve had two 65s but never a 64 so it proves I can play the game and I am looking forward to the weekend, especially the way I am swinging the club now.’’

Montgomerie, who insisted that ‘‘peace has broken out’’ with BBC Radio Five Live after giving a live interview to the reporter he insulted yesterday, was particularly pleased with the improvement in his putting.

He felt that cost him last year’s Open to David Duval, and he proved his point today by holing from 25 feet for the eagle, and again from 30 feet for the birdie at 15.

‘‘It was the putting which let me down last year, and David Duval can say the opposite,’’ said Montgomerie. ‘‘My putting let me down in this championship last year and hopefully I am putting a lot better now, and hopefully that won’t happen again.’’