The 36-year-old did so despite a fractured rib and torn muscle from his kayak training, as well as a twisted ankle picked up in taekwondo sparring.
Taufatofua beat Papua New Guinea's Steven Tommy, the only other entrant in his over-80kg class, 20–4 to secure a qualifying spot for Tonga. Tongan officials indicated to NBC that he would be selected for it.
Having first come to prominence as a taekwondo athlete in Rio when he entered the Maracanã Stadium shirtless, he changed course and managed to qualify for his first Winter Olympics in PyeongChang in cross-country skiing, finishing 114th in the 15 km freestyle race.
In 2019, he teased that he was aiming to make it back to the Olympics in a new sport.
Announcing his decision, he told the Olympic Channel Podcast at the time: "I chose kayak because it's something close to my heart. It's something that Polynesians have done for a thousand years, travelling from island to island."
If he qualifies in kayak, he would become the first person to take part in three consecutive Olympics in three unrelated sports.
He would also be the first person to compete in two unrelated summer sports at a single Olympics since 1952, when Aristidis Roubanis played basketball and took part in athletics for Greece.
There is one final qualifying spot available in his 200m single kayak event at the ICF Canoe Sprint World Cup 2 in Germany in May.
If he does not qualify there, he would have to rely on Tonga being granted a Tripartite Commission Invitational place, given in selected sports to countries who have sent small delegations to the two previous Games.