Wow, what a win by LZJ. He played some of his best badminton and he was in the zone. I never would have predicted LZJ winning, nevermind winning in 2 sets too. For Momota, I suspect Kanta Tsuneyama and Kenta Nishimoto are not pushing Momota enough in training or in the domestic Japanese tournaments. Momota needs to be playing the top players in the world - players such as CTC, Viktor, Antonsen, Chen Long, SYQ, Ginting, Christie, etc, who can push Momota to #1 again. Also, the coaches of other countries will game plan in detail against Momota. I'm not sure if Kanta Tsuneyama and Kenta Nishimoto are doing detailed game plans against Momota in the domestic Japanese tournaments - and even if they are, Momota probably knows their styles anyways because they play and train so much together. But it's different on the international circuit where Momota doesn't know the play styles of the other players as well. LZJ said he did a lot of studying and preparation against Momota:
https://www.japantimes.co.jp/sports/2021/03/20/more-sports/no-1-kento-momota-upset-england-open/.
I'm going to assume Momota isn't suffering from any major injuries since the car accident (all pro players always have some type of lingering minor injury but they can usually play through those nagging minor injuries and win). Only Momota, his coaching staff, and his trainer would know if he has outstanding injuries that cost him loss against LZJ. What I did see though was a few times where Momota was comfortably behind the shuttle in the backcourt, and then he hit a shallow return, which allowed LZJ to smash the winner. I think there were some net plays too where Momota was comfortably at the net and the return by LZJ was not particularly tight, but he did a short lob to the back and LZJ just smashed those (this is excluding the tight net shots that LZJ hitthat were very difficult to return by Momota - I'm talking about a non-tight net shot that Momota would have routinely lobbed it to the back court in the past, but for some reason, Momota lobbed it short to the backcourt).
It seemed like Momota had difficulty reading LZJ's game, Momota was less consistent than usual, and shots that should have been routine for Momota became poor shots (ie. some shots to the backcourt that were just short).
Anyways, I had Momota as the #1 favorite to win gold at the Olympics. After his performance today, I'm not so sure anymore. We need to see Momota play in more high level international tournaments (not domestic Japanese tournaments). The good thing for Momota is that there is still time for him to fix his game and play like the world #1 he was before his car accident. Lucky for Momota, he is finding out now (it would have been better if he found out in January but whatever, there is still time until the Olympics). Imagine if Momota missed this tournament and maybe the next few tournaments, then he walks into the Olympics thinking he is still the best player in the world but then getting upset by LZJ or some other player? 4 months is plenty of time for Momota to get his game back. But he needs to play in more top level tournaments so he can get his anticipation and consistency back to where he was before the car accident.