Whakakihia te rerenga e whai ake nei: Ko te tau 2002 i tohu i te angitu nui mo Kosgei i roto i te ara me te huarahi. I te marama o Mei, i arahi ia i te kapa Kenya ki te wikitoria i te
2002 IAAF World Half Marathon Championships me te waa o te 1:00:39. I whiua e ia a Jaouad Gharib ki te wikitoria i te whakataetae i tana whakamatau tuatahi i te tawhiti hawhe marathon. Ko tana angitu i te wa tuatahi kaore ia i huri wawe i a ia: "Kua huri taku arotahi mai i te tere tere ki te 10,000 mita... Tērā pea i roto i te rua, e toru tau ka tīmata ahau ki te whakaaro ki te rere i te marathon". Ko Kosgei te toa o Kenya i runga i te 10,000 mita i taua raumati, a ko tana whakamatautau i muri mai i te 2002 Commonwealth Games i Manchester, Ingarangi. I whakauruhia ia ki te whakataetae 10,000 m a ko ia te tuarua i muri i tana hoa whenua o Kenya a Wilberforce Talel <unk> Ko te waa mutunga o te 27:45.46 a Kosgei e whitu rau o te tuarua i muri i a Talel, nana nei i pakaru te rekoata o nga Taakaro mo te kaupapa.