He started with his first medal for Kenya at the 2011 African Junior Athletics Championships, where he was the silver medallist in a Kenyan 1–2 with Gilbert Kirui.

[4] He ran at his first Diamond League race soon after and his personal best time of 8:11.31 minutes (for fifth at the Meeting Areva in Paris) ranked him thirteenth in the world that year,[5] marking him out as one of Kenya's emerging talents.

He found himself behind Kenyan opposition on several occasions that year, coming in third at the Golden Gala,[10] fourth at the Olympic trials,[11] Meeting Areva and Memorial Van Damme, and fifth at Herculis.

[22][23] He was a narrow second to Koech at the IAAF World Challenge Beijing,[24] but came out top in national competition at the Kenyan Athletics Championships.

At the major events of the year, he was the favourite for the 2014 Commonwealth Games but was upset by fellow Kenyan Jonathan Ndiku, who beat Birech by two seconds, but he reversed that placing at the 2014 African Championships in Athletics to take the continental gold medal.

[25] On the circuit, he won the Diamond League races in Lausanne, Monaco, and Birmingham before going on to win the series final at the Memorial Van Damme, setting a new best of 7:58.41 minutes in the process.