He had his first win on the European Tour in 2009, and on the PGA Tour in 2010.
In 2011 at the age of 22, he became the youngest player ever to reach €10 million in career earnings on the European Tour.
By April 1997 he had already won his first major, the 1997 Masters.
"It got a little faster than I would have liked starting on about 16," he said with a smile.
"But I was able to hang in there." Johnson was 4 up with six holes to play when Rahm, a bold Spanish rookie with a big game, hit driver over the water and onto the 13th green to win the hole with a birdie.
He stuck a wedge close on the 15th for another birdie.
He had a successful amateur career, topping the World Amateur Golf Ranking for one week as a 17-year-old in 2007.
Later that year he turned professional and soon established himself on the European Tour.