He became a naturalized South Korean citizen in 2003, and was known as Lee Seong-nam while playing for Seongnam Ilhwa Chunma.

In December 2007 he returned to Russia and signed a two-year contract with Sibir Novosibirsk in the Russian First Division.

While not being selected for the final Russian squad, Laktionov was involved in the training camp for the 2002 FIFA World Cup.

Laktionov made his debut for Russia on 17 May 2002 in a friendly game against Belarus.

His son Nikita Laktionov made his debut as a professional footballer in 2019 at FC Rodina Moscow which Denis was managing.