Tokyo, Japan: Keita Nakajima signalled his title intentions with an opening three-under-par 67 in the Asia-Pacific Open Golf Championship Diamond Cup.

The number one player in the World Amateur Golf Ranking (WAGR) raced out of the blocks at Oarai Golf Club, finishing the day tied for sixth, just two strokes off the pace being jointly set by veteran Japanese golfer Hiroshi Iwata and his rookie compatriot Kaito Onishi.

The reigning Asia-Pacific Amateur Championship (AAC) winner, Nakajima is not only bidding to retain the title he claimed last year as low amateur at the Diamond Cup, but also to become the first amateur to win twice on the Japan Golf Tour Organisation (JGTO).

Nakajima’s maiden JGTO victory came at last year’s Panasonic Open, making him only the fifth amateur to win on the Japanese professional circuit.

Setting out from the 10th tee as one of the early starters, 21-year-old Nakajima reeled off seven pars before suffering a three-putt bogey at 17, his eighth of the day.

That setback proved to be the catalyst for a remarkable putting clinic over his final 10 holes during which Nakajima had nine one-putts on the slick, true greens, helping him to cover the front nine in four-under 31.

A total of 20 spots in the field are allocated for amateurs. Nakajima’s opening-round performance was matched by New Zealand amateurs Jimmy Hydes and Kazuma Kobori.

Co-sanctioned by the Asian Tour and the JGTO, the ¥100 million event is hosted by the Japan Golf Association (JGA) in partnership with the Asia-Pacific Golf Confederation (APGC), Kansai TV and Mitsubishi Corporation.

Courtesy of The R&A, this week’s winner will be rewarded with an exemption into July’s 150th Open Championship at St Andrews.

This is the 11th occasion that the Diamond Cup has been held at Oarai Golf Club, but the first occasion since 2013 when two-time AAC winner Hideki Matsuyama claimed the title, a matter of months after turning professional.