Koltsov won the Russian Qualifying Event for the 2015 PDC World Championship and beat Haruki Muramatsu of Japan 4–2 in legs in the preliminary round. He squared his first round match with Kevin Painter at 1–1 in sets, but could not win another leg after this to be defeated 3–1. He teamed up with Aleksei Kadochnikov to represent Russia at the World Cup of Darts and they lost 5–1 to Australia in the first round. Koltsov's bid to reach the 2016 World Championship was ended at the semi-final stage by Aleksandr Oreshkin. He dominated the Eurasian Darts Tour in 2016 by winning four and losing in one final of the six events staged. Kolstov and Oreshkin were defeated 5–3 by the Netherlands in the opening round of the World Cup, with world number one Michael van Gerwen praising Kolstov's play afterwards.