After making his way through the various youth levels at the club, he debuted for the senior team in a 4–1 home win over Lokomotiv Sofia on 11 September 2004, aged 15.

[2] In January 2010, Iliev signed for CSKA Sofia, but struggled to get into the main squad and spent loan spells at Minyor Pernik and Pirin Blagoevgrad, before joining Montana on a permanent basis in August 2011.

The 1–0 win against local rivals Botev Plovdiv was achieved with the only goal in 73rd minute scored by Alen Ožbolt (assist by Ante Aralica and pre-assist by Iliev himself).

On 2 August 2020, Iliev scored a last-minute goal against Ludogorets Razgrad, helping his team to a 1–0 win and a Bulgarian Supercup triumph.

He earned his first cap on 26 February 2020, playing the first half of the 0–1 home loss against Belarus in a friendly game.