Rotich won in two hours, 14 minutes and four seconds to take home a prize of Tw$1.2 million (S$50,135).
Kenyan, Hillary Yego came second on 2:17:00 while Jepkopol came next on 2:20:03.
The women's race was dominated by Kenyans, with Alice Jemeli Timbilil clocking in 2:34:55, to win.
She was followed by Carolyne Chemutai Komen with 2:36:17 and Viola Chepleting Bor with 2:38:29.
More than 100,000 runners took part in the event.