Despite playing in no fewer than 17 Open Championships between 1977 and 2002 the English golfer has never before played a major in the United States.
His appearance at Kiawah Island is one of Chapman's rewards for winning the Senior PGA Championship in May - a remarkable story in itself, but one to which he added another staggering chapter recently by lifting the Senior US Open as well.
It was a double worth £565,000 and because of the second of them he also has next June's US Open at Merion to look forward to.
Chapman's last major was in 2002 at Muirfield - and he was disqualified for a scorecard error in his second round.
His best finishes were 12th at Birkdale in 1991 and 13th at Troon in 1989, but Chapman also has clear memories of his debut at Turnberry in 1977 - the year of the 'Duel in the Sun' between Tom Watson and Jack Nicklaus.
"As an amateur (he was 18 at time) I'd come through qualifying at West Herts and then at Western Gailes in Ayrshire.
"I remember standing on the seventh tee looking out over the Ailsa Course, gazing at the huge crowds and thinking 'What on earth am I doing here?' - I felt totally out of my depth."
He shot 86 on the first day and 79 on the second, but even at 27 over par there was somebody 10 shots behind him. Three-time champion Henry Cotton, 70 by then, played for the first time since 1961 and had rounds of 93 and 82.
Chapman turned professional four years later after beating future major champion Hal Sutton twice in one day at the Walker Cup, but his European Tour career is mostly remembered for the fact that in 28 seasons he played 618 events and won only one of them.
For him to be playing in majors - real ones, not senior ones - in America now is simply the stuff of dreams.
There will be nobody in the entire field feeling they have nothing to lose quite like Chapman.