Korir, 30, who was second in last month’s Paris Half-Marathon, came home in a time of 2hr 05min 46sec, ahead of another Kenyan, Luka Kanda.
Seboka Tola of Ethiopia was third, with yet another Kenyan, Mike Kigen, fourth.
Kigen made the decisive breakaway 10km from home but he was reeled in by Korir, who set off in pursuit and caught him up 5km out before streaking away to leave Kigen trailing in behind the first three in the Bois de Boulogne.
Korir is the fifth winner to run under 2hr 06min in the French capital.
Ethiopia’s Kenenisa Bekele set the race record of 2:05:04 last year, beating the 2:05:10 run by Kenya’s Stanley Biwott in 2012.
Kenyans Peter (2:05.37 in 2013) and Vincent Kipruto (2:05:47 in 2009), have also broken the 2:06 barrier.