Ham closed with a 3-under 68 to finish 16 under. John shot a 66 while Ballester, Thailand’s Jazz Janewattananond (68) and Tomohiro Ishizaka (70) from Japan shared third.
The Korean’s performance is one of the most impressive in the 57-year history of Singapore’s National Open, considering a place in the game’s oldest major was on the line as well as valuable points on The International Series Rankings.
The weather also had a big part to play on Sunday when after three days of oppressive heat and humidity, the skies darkened and at 11: 47 a.m. play was stopped for just over three and a half hours due to lightning.
Ham started the day with a four-shot lead over John and when the interruption occurred they had completed seven holes with the Korean three ahead.
When play resumed at 3:30 p.m., Ham picked up where he left off by holing a 10-foot putt for par on the eighth that helped settle the nerves and was typical of his performance on the putting surface all week. He had another testing 4-footer for par on the next which he slotted home.
It was then that John really put the pressure on with a succession on big birdie putts. The Australian holed a 25-footer for birdie on the ninth hole, meaning Ham was two ahead with nine to play.
Ham lipped out for birdie on the 10th before John closed the gap to one when he made a brilliant birdie on the 11th, draining a putt from 15 feet.
The 13th then produced high drama when Ham assumed the upper hand by holing his bunker shot for a birdie. It looked like he would move two ahead with John facing a 40-footer for birdie. To everyone’s astonishment the Australian holed his putt to keep the pressure on his opponent.
The action continued at a pace when they both hit their tee shots close on the par-3 14th. Ham holed his from 12 feet before John followed him in from 7 feet to keep the gap at one.
They both faced makeable birdie putts on the ensuing hole, but both missed, John first from 18 feet then Ham from a slightly shorter range. On the par-3 17th again they both missed makeable birdie putts meaning Ham led by one with one to play.
On the par-5 18th Ham sealed the deal when he reached the back of the green in two and two-putted for birdie, while John made par – although he nearly holed his chip from just off the green for a 3.
Said Ham: “Honestly, I sweat a lot and struggle in the heat, so I just kept thinking: play quickly, get through it, and get back to the hotel as soon as possible.
“Of course you still need to hit good shots, but because it was so hot, I actually wasn’t overthinking the golf too much. That probably helped me stay relaxed. I just wanted to finish quickly, shower, and lie down under the air-conditioning.”
Ham becomes the second Korean to win the event. Younghan Song, now a member of Korean Golf Club on LIV Golf, was the first in 2016 when he beat then world No. 1 Jordan Spieth by one, also on The Serapong.
“My putting was really good today. I’d say the putter saved me for around six shots. Thankfully, the putter worked well and helped me keep the momentum going,” added the Korean.
It is the Korean’s first win on the Asian Tour, where he has only played 24 times since turning professional eight years ago, with 16 of those on home soil.
The impressive golfer’s textbook golf swing has previously brought him four wins on the Korean PGA Tour, the most recent being two years ago at the Golfzon-Toray Open.
For John it was yet another fine performance by one of Australia’s rising stars. He finished second on the 2025/26 Challenger PGA Tour of Australasia Order of Merit, thanks to three wins, while today marks his finest overseas performance.
Missing out on the title was made up for by getting into The Open.
“It’s an unbelievable feeling,” said the 23-year-old.
“I’ve wanted to play in major championships my whole life. I came close back home in Australia, so to come over here and get it done means a lot. It’s something I’ll never forget.
“My game feels like it’s in a really good place. Today was a different test mentally. The Open spot was definitely on my mind, but I felt like I managed it well. Looking back, it’s been an incredible year and I’m really grateful for the people around me who support and help me.
The Asian Tour moves swiftly on to the GS Caltex Maekyung Open next week – for one of Korea’s most prestigious events.
The tournament, which is celebrating its 45th edition, will be played at Namseoul Country Club, south Seoul.
Korea’s Doyeob Mun warmed up perfecting for his defense of the title today by shooting a fine 65 today to climb in to a tie for sixth.
Ryan Ang closed with a 66 to finish as the leading Singaporean, in joint 12th.
Top image: Josele Ballester of Fireballs GC during the final round of the Singapore Open at Sentosa Golf Club on Sunday, April 26, 2026 in Sentosa, Singapore. (Photo by Graeme McCubbin /LIV Golf)
The International Series has launched a new website and app, bringing users closer to the action with live leaderboards, player rankings, and full tournament coverage.