We saw the future at the Masters yesterday and it looked good. Trevor Immelman, the third-round leader, Brandt Snedeker, who was two strokes behind, and Paul Casey, who trailed Immelman by four strokes, are all younger than Tiger Woods. What is more, they were three of the four men who were leading Woods after 54 holes of the year's first major championship.

There is some historical significance in this. There has not been a major championship in recent memory in which so many of the leaders and so many of the men who have been ahead of Woods were younger than the world No 1. Usually Woods, who was born on December 30, 1975, is surrounded by rivals who are grizzled in golfing terms, men such as Woody Austin, who was 43 when he finished runner-up to Woods in the 2007 US PGA Championship.

In Woods's 13 major championship victories, only four times has he been older than his closest challenger after 54 or 72 holes. Sergio García, who was born in 1980, finished one stroke behind Woods at the 1999 US PGA Championship, trailed the American by four strokes after three rounds of the 2002 US Open Championship and was one stroke behind Woods at the 2006 Open after 54 holes. Luke Donald, who was born in 1977, was level with Woods after 54 holes of the 2006 US PGA Championship.

Here is another way of emphasising Woods's age dominance. Since he won the 1997 Masters, his first major championship, only three of the 43 major championships have been won by men younger than he was at the time: Ben Curtis (2003 Open), Geoff Ogilvy (2006 US Open) and Zach Johnson (2007 Masters).

To witness so many men younger than Woods at the head of a field in a major championship is revealing and suggests that the game is changing. From being surrounded by men who are older than he is, Woods must now start to get used to competing against younger rivals. If you wanted three men typical of professional golfers born since Woods, Immelman, Snedeker and Casey are as good as any. Immelman, 28, is South African and, before moving to the United States for his final grooming and transformation into a world-class player, spent six seasons on the European Tour, basing himself in Richmond, southwest London, as he steadily worked at his game.

In a sport that has a tendency to be inward-looking, he has a welcome perspective on life after having a tumour, found to be benign, removed from his stomach at a hospital near Cape Town last December. More than most, Immelman realises how lucky he is to be doing what he loves and something at which he is so good.

He was asked how the high of being at the top of the leaderboard at the Masters compared with the high of being on morphine in his time in the hospital. “It was a bit degrading when you have other people washing you night and morning,” he said. “I think I'll take leading the Masters. All I have wanted to do since I was 5 was win golf tournaments and, so, to go through something like that felt like a speed bump because I really wanted to keep going. I feel like I've been loaned a talent, not given one. I have realised that it can get taken away from you real fast.”

To judge from the look of enjoyment on his face when he plays golf, Snedeker, 27, appears to be having the time of his life. A talented player who appeared at Augusta as an amateur in 2004 and played all four rounds, Snedeker won nearly $2.8million (about £1.5million) on the tour in the US last year, in part because of his win in the Wyndham Championship. He was the tour's rookie of the year.

Casey, 30, can look contented on the golf course and, for much of the third round, he did. Like Snedeker and Immelman, he appears a man at ease with himself. “I feel very happy on a golf course,” Casey, 30, said on Saturday. “I love what I do. I can't wait for the sun to come up each day.”

Immelman's swing seems firm and controlled. Snedeker gives the ball something of a bash. Casey, with his stevedore forearms, overpowers holes, if not always all 18. All three men are following in the footsteps of countrymen who have won the Masters: countless for Snedeker, Gary Player for Immelman and Nick Faldo for Casey. Whatever happens at Augusta, they are going to be in professional golf for a long time yet.