[2] [3] He is best known for his highest career achievement at SEA Games 2017, breaking the national record for 100 M Men's Breaststroke last made in 2009 by Indra Gunawan, and won Indonesia's first Gold Medal for that event since 1993 by Wirmandi Sugriat.

In the 2017 Islamic Solidarity Games (ISG) event, Gagarin also won a gold medal which took place at the Baku Aquatics Center in Azerbaijan.

[4] In SEA Games 2017 held in National Aquatic Centre, Kuala Lumpur, Gagarin won his gold medal from 100m breaststroke, with a recorded a time of 1:01:76.

[3] His latest big achievement was PON Papua XX held in Lukas Enembe Stadium, Jayapura, where he won four gold medals and broke four game records.

[7] Currently, Gagarin is placed first rank in Indonesia's men's breaststroke event, holding his all time national records.