Mezue ahịrịokwu na-esonụ: Niyonkuru bidoro na asọmpi mba ụwa bụ na 2005 IAAF World Cross Country Championships. Ọ gbara asọmpi n'ọsọ ụmụ nwoke ndị na-eto eto wee mechaa nke iri atọ na atọ n'ime ndị na-eme egwuregwu 133 n'oge nkeji iri abụọ na ise na sekọnd iri atọ na abụọ. Na 2005 Jeux de la Francophonie Niyonkuru gbara asọmpi na mita 10,000. Niyonkuru gbara nke anọ n'oge nkeji 29 na sekọnd 18.08, naanị sekọnd 0.03 n'azụ onye meriri ọla ọcha, onye Morocco Abderrahim Goumri. Niyonkuru mechara sọọ mpi na 2006 World Junior Championships. Ọ gbara onye nke ise n'ọsọ 10,000 mita n'oge nkeji iri abụọ na asatọ na sekọnd 59.92. Ọ nọ na sekọnd 6.63 n'azụ onye meriri n'ọsọ ahụ, Ibrahim Jeilan nke Etiopia. N'afọ 2007, Niyonkuru gbara asọmpi na 2007 World Cross Country Championships n'ọsọ ụmụ nwoke. O ji nkeji iri abụọ na anọ na sekọnd iri ise na isii gbaa ọsọ. O ji sekọnd iri anọ na itoolu na-eso onye meriri ọlaedo, onye Kenya bụ Asbel Kiprop. Na 2009 World Military Track and Field Championships, Niyonkuru meriri ọla ọcha na mita 10,000. Oge ya nke nkeji 29 na 37.14 sekọnd bụ sekọnd 23.67 n'azụ onye nrite ọla edo, Essa Ismail Rashed nke Qatar. Niyonkuru ji sekọnd 4.97 n'ihu onye meriri ọla nchara, onye Tunisia El Akhdar Hachani. Niyonkuru meriri ọkara marathon nke Auray-Vannes na 2015 na oge nke otu elekere, nkeji atọ na sekọnd iri abụọ. Na 2016 Summer Olympics, Niyonkuru gbara asọmpi na
marathon ụmụ nwoke na 21 Ọgọstụ 2016, mana emechaghị ọsọ ahụ. N'afọ 2017, ọ gbara asọmpi na marathon ụmụ nwoke na 2017 World Championships na Athletics, na-etinye 71st na 2:42:27.