Besides DPMM, Shah Razen has also played for
AH United, non-league Viva Rangers,
Wijaya FC, as well as a short trial with Indian club
Sporting Clube de Goa. He was also Brunei's top scorer in the
2006-07 Malaysia Super League with 21 goals, back when DPMM were playing in the
Malaysian Premier League. When DPMM joined the
S.League starting in 2009, Shah Razen helped the club to win the
Singapore League Cup twice, in 2009 and 2012. He was used sparingly by
Steve Kean in the
2014 campaign, only starting two games and notching two goals as the team won the
League Cup for the third time and only missing out on the S.League title in the final round of fixtures. In the 2014 close season, he was poised to join
Perak FA, which would have linked him up with former manager
Vjeran Simunić who was then the Perak FA manager. The move did not materialise. On 10 June 2021, Shah Razen stated in an Instagram post that the upcoming
2021 Brunei Super League season would be his last one in DPMM stripes. He made his first appearance of the season against
Rimba Star FC on 4 July, coming on to replace
Andrey Varankow. He managed to get a hat-trick to contribute to a 15–0 victory. This was his first hat-trick since 14 February 2007 against
NS Naza in the
2006–07 Malaysia Super League. On 4 December 2022, Shah Razen scored the winning goal in a 2–1 victory over
Kasuka FC in the final of the
2022 Brunei FA Cup, to end a remarkable season in which he scored a total of 19 goals in the competition. Shah Razen ended his 17-year stay at DPMM in 2023 and joined Kasuka, reuniting him with his brother
Adi. He scored on his debut in the opening match of the
2023 Brunei Super League on 3 March against
MS PPDB which finished 4–0. On 17 November, Shah Razen gained his first local championship medal with Kasuka after being undefeated in all of their matches. Shah Razen came back to DPMM in 2025, lacing up for the team that plays in the
Brunei Super League. He made his DPMM II debut on 19 January against
Jerudong FC in a 5–0 win. On 6 April, he scored a hat-trick in a 12–0 win over PKT FT in the
2025 Brunei FA Cup. DPMM II would go on to win the cup on 18 May. ==International career==