Newcomer Kho claims maiden Asian Tour victory for Hong Kong
Kho only turned professional in January but held off New Zealand's Michael Hendry to win by two strokes at a soggy Hong Kong Golf Club and claim a place at this year's Open Championship.
Organisers reduced the tournament to 54 holes overnight after heavy rain and lightning led to play being called off on Saturday.
The course was still suffering the effects of the bad weather when play resumed on Sunday, with Kho holding a four-shot lead over Miguel Tabuena of the Philippines.
"Being at home, in front of everyone, having my parents here, it just means the world to me. I want to say thank you to everyone," Kho said.
"I can't put into words how grateful I am to have this opportunity. The fans gave me a lot of momentum, thank you to Hong Kong," the 22-year-old said.
Kho struggled when play resumed on Sunday, dropping shots at the third and sixth holes to see his lead over Tabuena cut in half.
To the delight of his home fans, Kho got his game back on track by holing out from about 45 metres for a much-needed birdie at the par-four ninth hole.
Tabuena, fresh from winning the DGC Open in New Delhi last week, started disastrously with a double-bogey six at the first and, despite a birdie two at the next hole, never really recovered.
South Korea's Bio Kim and Australian Travis Smyth raced up the leaderboard while Kho steadied and Tabuena faltered.
Another bogey at the par-four 11th saw Kho's lead cut to a single shot over the hard-charging Smyth and another Korean, Yoseop Seo.
Successive birdies at the next two holes, including almost holing his tee shot at the 12th, restored Kho's lead to three and he finished with an even-par 70 for a three-round total of 198.
"I definitely wasn't fearless, I was nervous, which was perfectly natural in the moment, but I said to myself I will be a better player by the end of it," Kho said.
Importantly, victory at the inaugural World City Championship, only Kho's third professional tournament, earned him a place in The Open Championship at Royal Liverpool in July.
Kho's playing partner Hendry calmly compiled a two-under round of 68 for second place, with Smyth finishing third on 201.