The Japanese Olympic champion re-gained the -73kg crown as Japanese-born Deguchi sealed gold for Canada in the women's -57kg class.
Shohei Ono is simply unbeatable.
The reigning Olympic champion demonstrated why many regard him as the world's best pound-for-pound judoka, by winning his third -73kg world title on Tuesday (27th August).
Ono dominated every round with his technical prowess to earn Japan their third gold medal - and eighth overall - at these judo worlds.
He's also clear favourite to retain Olympic gold at the same Tokyo venue at the Games 2020.
"I wanted to perform beyond everyone’s expectations and get the crowd into it at the Budokan", the 27-year-old told reporters after winning his first world crown since 2015.
"I’d give myself a 73 out of 100. People saying that I’d cruise to the championship got to me, so that’s why I’m not giving myself the full mark. I need to sharpen up, especially now that I’ve won. I feel like I have far more to offer in terms of performance."
"I hope to be back at the Budokan next year and take the highest place on the podium" - Shohei Ono
"I know how tough that is [to repeat as Olympic champion] more than anyone, which is why I want to be back in this place next year."
"From the first round all the way to the final, his judo was exceptional. He was simply dominant in winning the championship", Japan's men's coach Kosei Inoue told reporters about Ono following the win.
"The talent is obvious, but the training he puts in, in terms of quality and volume, is second to none.This season, he did all his homework from the previous year and I would say he’s even stronger than he was in Rio now.
"I know his goal is to win another gold medal in Tokyo next year [at the Olympics] so he only needs to stay focused and not let up."
"He virtually has no weakness" - Japanese men's coach Kosei Inoue
Last March, Ono graduated in physical education at Tenri, one of the most prestigious judo universities in Japan, and his dissertation was on o-soto-gari, his favourite judo techniques.
"If I could make an analogy between boxing and judo, he’s an all-round judoka. He has the whole package." double Olympic medallist Neil Adams told the Olympic Channel.
"Ono has it all. He has an equal ground work and standing game. He’s tactically very aware. On top of that, he’s able to come in front of his own crowd here and be very, very calm.
"He knows how to play to win. He can throw both sides, he has such a wide range of techniques, probably 7-8, that score ippon: different throws, like uchi-mata and o-soto-gari, sometimes holding somebody down…He can execute them at the highest level against the highest level of opponents."
"Japanese judo fighters normally don’t have a great physicality, but he’s also strong." - Double Olympic medallist Neil Adams to Olympic Channel
In the first bronze-medal final, Russia’s Denis Iartcev beat Tajikistan’s Behruzi Khojazoda to take his first medal in a world championship.
He was joined shortly after by Azerbaijan’s Hidayat Heydarov, who defeated Somon Makhmadbekov from Tajikistan.
Japanese-born Christa Deguchi claimed the first world title for Canada at these IJF World Champs.
The 23-year-old switched allegiance to her father's country in 2017, in order to have a better chance at qualifying for next year's Olympics.
Deguchi secured a podium finish at her first event of last year in Baku.
Her return home couldn’t be more triumphal, as she defeated reigning world champion and top seed Tsukasa Yoshida in the women’s -57kg final.
Deguchi received a rousing round of applause from the home crowd at the Nippon Budokan.
"I was a little surprised to see so many Japanese people cheering for me," she told reporters after her win.
"I’m part of the Canadian team but the people in Nagano still support me so much. I’m grateful they root for me regardless of what my nationality is."
Rio 2016 gold medallist Rafaela Silva also added bronze to her medal haul as she overcame Ivelina Ilieva of Bulgaria in the small final.
The Brazilian is working her way back to form and targeting Tokyo 2020 success after rediscovering her focus.
Polish 2018 European U23 champion Julia Kowalczyk won the other bronze medal, with victory over Ivelina Ilieva of Bulgaria.