|Date of birth||5 April 1987|
|Place of birth||Tallinn, Estonia|
|Height||1.90 m (6 ft 3 in)|
|Tallinna Jalgpalli Klubi|
|2003||Tallinna Jalgpalli Klubi II||2||(1)|
|2013||Ceahlăul Piatra Neamț||3||(0)|
|2014||JK Narva Trans||17||(0)|
|2014–2015||JK Ganvix Türi||24||(1)|
|* Senior club appearances and goals counted for the domestic league only and correct as of 6 March 2016.
In January 2006, Lepmets moved from JK Merkuur Tartu to FC Levadia Tallinn in a switch deal, which saw fellow goalkeeper Aleksandr Djatšenko move the other way. He signed a new one-year deal with the club in December 2010. Until then he had mostly played for the reserve team and his first team action was severely limited. Lepmets stated the 2011 season as the main keeper, but fell behind veteran Martin Kaalma in the second part of the season and was released at the end of the season.
He was on trial with Romanian top division side FC Politehnica Timișoara in January 2011, and signed a contract with the team on 1 February 2012. He did not make any appearances for the first team in 2011–12 season, featuring three times on the bench, and gathered playing minutes for the reserve team in Liga III. After club was relegated to Liga II due to denied top division license by Romanian Football Federation, despite finishing second, and Costel Pantilimon's move to Manchester City, he became the new number one. On 20 August 2011, Lepmets made league debut in a 2–0 victory over FC Bihor Oradea. He was the first-choice keeper until the beginning of April 2012, getting 11 clean sheets in 20 league appearances in that time. He then refused to play due to unpaid wages and only featured in two more games for the team. After winning the 2011–12 Liga II season with Poli Timişoara, the player, alongside teammates Rover Cârstea and Rafael Rocha, moved to CS Concordia Chiajna.
- "Sergei Lepmets FC Levadiasse" (17 January 2006) (in Estonian). Soccernet.ee. Retrieved 26 August 2012.
- "Lepmets ja Malov pikendasid lepinguid" (in Estonian). FC Levadia Tallinn. December 2012. Retrieved 26 August 2012.
- "Meistrite liiga kohta jahtiv klubi kutsus Eesti väravavahi testimisele" (in Estonian). Postimees. 11 January 2011. Retrieved 26 August 2012.
- "AMETLIK: Lepmets sõlmis Timisoaraga lepingu" (in Estonian). Soccernet.ee. 1 February 2011. Retrieved 26 August 2012.
- "13 cluburi din Liga I au primit licenţa pentru sezonul 2011–2012" (in Romanian). Romanian Football Federation. 31 May 2011. Retrieved 26 August 2012.
- "City sign Romanian keeper Pantilimon". Manchester City F.C. Retrieved 11 August 2011.
- "Lepmets alustas hooaega nullimänguga" (in Estonian). Postimees. 20 August 2011. Retrieved 26 August 2012.
- "Sunnitud pausi pidanud Lepmets mängis taas Politehnica eest" (21 May 2012) (in Estonian). Postimees. Retrieved 26 August 2012.
- "Palgata Lepmets tahab Timisoarast lahkuda" (in Estonian). Soccernet.ee. 15 April 2012. Retrieved 26 August 2012.
- "Lepmets vahetas klubi" (in Estonian). Soccernet.ee. 8 June 2012. Retrieved 26 August 2012.
- "Lepmets alustas liigahooaega põhiväravavahina" (in Estonian). Soccernet.ee. 23 July 2012. Retrieved 26 August 2012.
- "Rüütli avaldas koosseisu esimesteks MM-valikmängudeks" (23 August 2012) (in Estonian). Estonian Football Association. Retrieved 26 August 2012.
- "Kõik Eesti internatsionaalid" [All Estonian internationals] (in Estonian). Eesti Jalgpalli Liit.