Japanese teenager Ryo Hisatsune upstaged many of the big-name players in this week’s International Series Thailand to take the halfway lead at Black Mountain Golf Club.

The 19 year old, who turned professional at the end of 2020, shot a six-under-par 66 for an impressive tournament total of 14 under.

He leads by one from Koreans Sungyeol Kwon and Doyeob Mun, who both carded 66s.   

A shot further back is reigning Asian Tour number one Joohyung Kim (68) and Taehee Lee (pictured) (64) from Korea, South African Jaco Ahlers (63), Thailand’s Chanat Sakulpolphaisan (66) and Tirawat Kaewsiribandit (65), and American Todd Baek (66).

“My course management today was very good. I am very happy,” said Hisatsune, who has his girlfriend Rirua on the bag.

“It was a so hot today, I am not used to this.”

He fired seven birdies and dropped just one shot.

A rising star of the Japan Golf Tour Organization he recorded six top-20 finishes during his rookie season in Japan last year and could well be a threat at the weekend.

Said Mun: “I am disappointed not to birdie the last. My chip should have been better so I could have made birdie and birdied the last three. Two more rounds to go though and so still a long way to go.”

Kim, also 19, is lurking ominously behind the leaders although feels his best is still yet to come in what is the first of 10 International Series events this season.

“To be honest I felt like I left a lot of shots out there today. It is still an under par round and it’s going to give me a chance,” said Kim.

“You can get a bunch of birdies out there, so you have to hit it close and give yourself a lot of opportunities. Everything needs to work well here. To be honest the last two days have not been the best that I have had but to still be here in contention is a good feeling.”

The Korean claimed Asian Tour Order of Merit title in January, helped by winning The Singapore International before finishing joint second in the season-ending SMBC Singapore Open.

Ahlers, a nine-time winner on South Africa’s Sunshine Tour who has been playing in Asia on and off for the past 10 years, fired an eagle, nine birdies and one bogey for the lowest round of the day.

He said: “I played pretty much the same as yesterday but made a lot more putts. I had 31 yesterday and 23 today. It is eight different. That’s just the name of the game. 

My form has been good recently, it’s been solid, not 63-type but plugging along, top 10 here, top 10 there. I just needed the putting to work, and it did today.”

India’s Karandeep Kochhar and Korean Bio Kim are a stroke further back after rounds of 68 and 69. 

The halfway cut was made six under, which was one shot short of the record set at the New Zealand Open in 2018.

Thailand’s amateur star Ratchanon ‘TK’ Chantananuwat made the cut for the sixth successive time on the Asian Tour on the day he turned 15 years old.

He shot a 68 to make it through to the weekend on six under.