Sergejs Semjonovs was one of the most reliable defenders in Daugava Rīga coached by Jānis Skredelis in mid-1980s when the club was one of the strongestsides in the Soviet first league. He played 9 seasons with Daugava, capping 340 appearances and scoring 3 goals. After the collapse of the Soviet Union Semjonovs played for some time with a club in Poland, in 1995 he retired from playing and switched to coaching.