The 27-year-old Momota had pulled out of his group A opening match against India's Lakshya Sen at the World Tour Finals in Bali, Indonesia after sustaining the back injury during training
Parupalli Kashyap went down 11-21 14-21 to Loh Kean Yew of Singapore to bow out of the competition.
The final was close in the first round, but the Japanese ace managed to build a strong defence as Antonsen repeatedly made unforced errors.
BWF World Tour Finals: Viktor Axelsen, Kento Momota lead badminton's return to Asia for season finale
Olympic silver medallist Chen Long will be missing, along with all players from China, for the first of three back-to-back events on the resort island of Bali beginning Tuesday.
Unseeded South Korean Heo Kwang-hee beat Momota 21-15, 21-19 to end his gold-medal bid after just two games, a day after Japanese tennis superstar Naomi Osaka also made an early exit.
Praneeth, who had ended India''s 36-year-long wait for a men''s singles medal at the world championship with a bronze in 2019, has reasons to get anxious having returned false positive during the Thailand Open in January.
Tokyo Olympics 2020: Tough knock-out challenge awaits PV Sindhu; difficult draw for Sai Praneeth, Satwik-Chirag
PV Sindhu has been drawn into an easier looking group but on her way to the final, she could face Akane Yamaguchi and Tai Tzu Ying.
Tokyo Olympics 2020: Japanese badminton ace Kento Momota 'positive' about Games debut after several career mishaps
World number one Momota was banned from Japan's Rio Games team in 2016 for illegal gambling, and was almost forced to retire last year after a serious car crash.
All the players and officials coming from South Africa, Brazil, Middle East and European countries including UK will be serving a seven-day quarantine period
Malaysian badminton legend Lee Chong Wei came achingly close to winning gold but never achieved it, picking up three Olympic silvers during his career.
All England Open 2021: Lee Zii Jia could prove worthy successor to Lee Chong Wei; Japanese armada scores big
Lee Zii Jia won the All England title at the expense of the two top-notchers - Viktor Axelsen and Kento Momota - who have been at the forefront of the sport for the past three years
All England Open 2021: Viktor Axelsen sets up final with Malaysia's Lee Zii Jia after beating Anders Antonsen in semis
Axelsen got the better of an all-Danish semi-final, coming from behind to beat Anders Antonsen 16-21, 21-7, 21-17.
The draw has opened up for Lee, who will face Mark Clajouw of the Netherlands in the semi-finals.
All England Open 2021: Indonesia withdraw after COVID-19 case on flight; Kento Momota makes winning return
Indonesia's badminton team were forced into isolation by UK coronavirus contact-tracing rules, forcing the team out of the All England Open.
BWF World Tour Finals: PV Sindhu drawn with World No 1 Tai Tzu-ying, local favourite Ratchanok Intanon
Tai, former world champion Ratchanok and Olympic silver-medallist Sindhu were grouped together with Thailand's Pornpawee Chochuwong for the round-robin stage of the biosecure tournament in Bangkok.
There is no doubt that the world badminton body would have been influenced by the compulsion of holding these three tournaments in a delayed Olympic qualification year, and also by the fact that other sports like tennis and cricket have been holding major events successfully, without causing a spike in Covid-positive cases.
Momota was looking to make his international comeback in Bangkok after almost a year out following a car crash that left him with serious injuries.
Kento Momota came from behind to beat world number 11 Kanta Tsuneyama 18-21, 21-12, 21-17 in Tokyo, marking a successful return from the accident that left him fearing his career might be over after fracturing an eye socket.
Momota beat Koshiro Moriguchi 21-12, 21-14 in the first round, marking his return from the accident that left him fearing his career might be over after fracturing an eye socket.
Momota will compete at the All-Japan national championships in Tokyo in late December before playing in the Thailand Open early in January