SIEM REAP (Cambodia) (AFP) - Japans Kenichi Kuboya opened his campaign strongly by posting a flawless seven-under-par 65 to take the first round lead at the Johnnie Walker Cambodian Open on Thursday. Thailands Atiwit Janewattananond, who made history by becoming the youngest player at 14 years and 71 days to make the cut at the Asian Tour season-opener in February, carded a 66 for second place. Bangladeshs Siddikur, who goes by one name, and defending champion Marcus Both of Australia scored matching 67s to share third place at the 300,000-dollar event. Kuboya, who teed off in the front-nine in the morning, posted his first birdie on the par-four fourth before adding successive birdies on the eighth and ninth holes to reach the halfway mark in 33. He birdied holes 10, 12, 16 and 17 after the turn, giving the Japanese a one-shot cushion going into the second round. I like this golf course as it really suits my game. Although the winds were picking up mid-way through my round, I still putted really well and I believed that gave me the confidence to do so well today, said Kuboya. Meanwhile Atiwit, who turned professional at the Kings Cup just a fortnight ago, got off to an encouraging start but said he was planning to adopt a defensive approach for his second round at the Phokeethra Country Club. I feel that Im not hitting the ball long enough. As such, I dont plan to go on the offensive and attack the pins as some of these shots may cost me dearly, said the young Thai, who posted seven birdies. I hope to continue what Ive done today and hopefully itll be another good round tomorrow, added Atiwit, whose only blemish to his card was a bogey on the par-four 10th. Siddikur continued to make good on his promise to spearhead the rise of golf in Bangladesh with another inspired performance. Starting on the back-nine, Siddikur posted three birdies on holes 12, 13 and 17 to reach the turn in 33. He continued his birdie blitz on the par-five second and fourth hole to return home comfortably in 67. Playing conditions were perfect today and I couldnt have asked for a better start, said Siddikur. Another strong favourite, Both put up a stout defence of his title, enjoying a blemish-free round, marking his card with birdies on the fourth, eighth, ninth, 10th and 12th holes. You tend to feel a little bit of pressure especially when youre the defending champion, said the 31-year-old Australian. But once I got the first tee shot somewhere in the middle of the fairway, I got more relaxed and did not feel that anxious any more.