His first Olympic appearance was at the 1920 Antwerp Games when he was eliminated in the second round of the featherweight class after losing his fight to James Cater.
At the Amsterdam Olympics in 1928, Nielsen tried to defend his Olympic title in the lightweight division but lost in the semifinal to the eventual gold medalist Carlo Orlandi. Nielsen also lost the bronze medal bout to Gunnar Berggren and thus finished fourth.
1920 Olympic results
Below is the record of Hans Jacob Nielsen, a Danish featherweight boxer who competed at the 1920 Antwerp Olympics:
Round of 32: bye
Round of 16: lost to James Cater (Great Britain) by decision
References
^"Hans Nielsen". Olympedia. Retrieved 5 August 2021. Full name: Hans Jakob Nielsen
^Evans, Hilary; Gjerde, Arild; Heijmans, Jeroen; Mallon, Bill; et al. "Hans Nielsen". Olympics at Sports-Reference.com. Sports Reference LLC. Archived from the original on 3 December 2016. Retrieved 4 November 2018. Full name: Hans Jakob Nielsen
1904: 125–135 lb (56.7–61.2 kg) · 1908: 126–140 lb (57.2–63.5 kg) · 1920–1936: 126–135 lb (57.2–61.2 kg) · 1948: 58–62 kg · 1952–2008: 57–60 kg · 2012: 56–60 kg · 2016: 57–60 kg · 2020–2024: 58–63 kg · 2024–: 58–63.5 kg