UPDATE 1-Golf-Japanese schoolboy Ishikawa gets jump on Immelman

(Adds Imano quote, detail)

TOKYO, Nov 13 (Reuters) - Japanese schoolboy Ryo Ishikawa fired an opening 66 to get a head start on U.S. Masters champion Trevor Immelman at the Taiheiyo Masters on Thursday.

The 17-year-old, who won his first tournament as a professional earlier this month, reached the clubhouse three clear of South African Immelman in Shizuoka.

Ishikawa ignited his six-under-par round by draining a snaking 25-foot eagle putt on the 11th after starting his round on the 10th hole.

"The eagle got me going," Ishikawa told reporters. "It was kind of a bonus because I wasn't going for an eagle on that hole. I think I played even better than the score shows."

Fellow Japanese Shingo Katayama, known for his colourful cowboy hats and belts, shot a 67 for a share of second place with Yasuharu Imano.

"He's got a little bit of an aura like Tiger Woods used to have as a junior," Imano said of Ishikawa.

Immelman, who won his first major title at Augusta National in April, returned a 69 in benign conditions against the backdrop of Japan's Mount Fuji.

Ishikawa won the ABC Championship earlier this month, his first title since turning pro at the start in January, only to miss the cut last week.