[1] In the 2011 SEA Games, Ridhwan represented Singapore and won a bronze medal in the 60kg boxing event after being eliminated by Mandiangan Matius of Indonesia in the semi-finals.
[3][4][5] In the 2013 SEA Games, Ridhwan won a bronze medal in the 60kg boxing event after being eliminated by Junel Cantancio of the Philippines in the semi-finals.
[3][6] In the 2015 SEA Games, Ridhwan won a bronze medal in the 56kg boxing event after being eliminated by Tanes Ongjunta of Thailand in the semi-finals.
[8] In late 2015, Ridhwan went for a coaching course while on the International Olympic Committee's scholarship, but realized on the first day that he did not want to give up actually boxing.
[8] In April 2017, Ridhwan defeated Waldo Sabu of Indonesia via knockout in the second round to win the World Boxing Association (WBA) Asia Featherweight Championship.