Tsehay Gemechu gained her first international experience at the Delhi Half Marathon 2018, where she won with a course record of 1:06:50 h. The following year, she set a new national record in Valencia in the 10 km road race with 30:15 minutes and at the 2019 World Cross Country Championships in Aarhus she finished sixth in 36:56 minutes and secured the gold medal in the team standings. In August she took part in the 10,000 meter run at the Africa Games in Rabat , where she won in 31: 56.92 minutes.
In 2019 she won the New Delhi Half Marathon for the second time in a new course record time of 1:06:00 h.