Hara, who works and lives in Ho Chi Minh City, ran the 42km in 3hr13.52 min to win the trophy in his first race in the UNESCO-recognised world heritage site.
“I am so happy today. I have not run a marathon for 10 years,” Hara told Viet Nam News after the race. “It’s also the first time I raced in Hoi An and visited the town. The track is very cool today.”
Australian Patrick Bugg Stephen came in second with a time in 3hr21.23min, ahead of Vietnamese Dam Trong, in third place with 3hrs 22.50min.
Stephen’s wife, Kim Bugg, also ranked second in the women’s half marathon (21km).
In the women’s 42km, Thai Prachayanipon dominated with a time in 3hr43.19min, 47 minutes faster than the runner-up, Tamae Harada from Japan (4hr30.7min), and Malaysian Chiew Tai Ong, in third with 4hr33.6min.
In the men’s 21km, Verdickt Gertjan from Belgium finished first, while Vietnamese Pham Thi Tho took the women’s category.
The marathon, which was hosted for the first time in Hoi An, drew around 1,500 runners, mostly foreigners, competing in the men’s and women’s 42km, 21km 10km and fun-run 5km categories along a beach track and in the town’s old quarters.
The race was held under the sponsorship of Index Creative Village, Bangkok Airways, Greenhat, and FabMotion.
Last year, Index Creative Village from Thailand and Quang Nam province agreed on co-operation to boost Thai tourism to destinations such as Hoi An’s old town, the My Son Sanctuary and the Cham Island-Hoi An biosphere reserve.
Hoi An hosted 1.7 million tourists last year.