During the 2015 Southeast Asian Games, Ng represented Singapore, attaining a bronze medal in the Men’s -54 kg.

In 2016, Ng represented Singapore in the Asian Taekwondo Olympic Qualification for the 2016 Summer Olympics in April 2016, where he lost 7–4 to Sergio Suzuki from Japan in the last sixteen and did not manage to qualify.

During the 2017 Commonwealth Taekwondo Championships, Ng won gold in the men’s -58 kg category, against competitors from more than 13 countries. Ng also claimed a silver medal in the Canada Open International Taekwondo Championships that same year.

In 2019, Ng represented Singapore in the 2019 Southeast Asian Games in the Men’s -58 kg Kyorugi category. Ng obtained a silver medal, achieving Singapore’s best results for Men’s Kyorugi since 1999.

It was reported that international governing body, World Taekwondo (WT) had found evidence of Lim Teong Chin (then General Manager of STF) and Wong Liang Ming (then Secretary General of STF) in violation of several articles in the WT code of ethics. In particular, Wong found to have violated Article 6 (Ban on harassment). WT also place the STF under preliminary suspension as its affiliate, and sought the Singapore National Olympic Council (SNOC) to review the situation. The SNOC suspended the STF as its affiliate as well. Wong and Lim had since left the STF. The SNOC appointed to an interim committee to oversee the STF and implement recommendations made by SNOC and WT to improve the management of the association. On 27 September 2019, Ng announced that matters have been resolved, with a statement on the STF’s website that Ng was a “commendable athlete whose athletic performance should not be downplayed”.

In an effort to attract sponsors to fund his dreams of competing in the 2020 Olympic Games, Ng has been using Instagram to gain media coverage. His Instagram account, featuring videos applying his skills in taekwondo to other sports, such as table tennis, bowling and basketball, has gained a following of 47,500 people on Instagram. His presence in social media was featured on Singaporean newspaper The Straits Times, as one of Singapore’s most followed athletes. Ng has also started using China’s popular video sharing app Tiktok to “get more young people interested in taekwondo”, and to share his love for sports through educational content. His creative videos won him the All-Star Southeast Asia 2019. He has been immensely popular on the app, amassing followers to become Singapore’s top Tiktok creator having become the first to achieve a whooping 1 million followers.

In an article by Singaporean community news website Mothership.sg, Ng’s obstacles in his bid to compete in the 2020 Olympics Games were detailed. He faced challenges by Singapore’s national governing body for Taekwondo, Singapore Taekwondo Federation (STF) who allegedly called his achievements “paltry”. Faced with the lack of support by the STF and a lack of a national team coach for more than a year, Ng had to finding his own opportunities, training with the South Korean, Norwegian and Taiwanese national teams. The STF claimed to have approved a sponsorship of S$30 thousand in November 2018 for Ng to take a year away from studies to train full-time. However, STF did not deny that Ng had only been informed of the sponsorship in January 2019 when it was too late to excuse himself from full-time studies. Ng’s carding status, which puts him under Sport Singapore’s Athlete Support Scheme, had been revoked. The decision was based on various sources such as input by the STF. There was also a delay of his application submission, allegedly due to the STF’s failure of a prompt response. Following the articles, other national team athletes have stepped up to share their grievances about their training under STF, including the inadequate coaching and lack of safe avenues for feedback.