There are not many sports that can keep an audience enraptured through 45 minutes of ceremony before the first point is even contested.
And yet, the intricate traditions unfolding in a small clay ring - virtually unchanged in hundreds of years - managed to do just that.
Welcome, then, to the Grand Sumo Tournament - a five-day event at the Royal Albert Hall featuring 40 of the very best sumo wrestlers showcasing a sport which can date its first mention back to 23BC.
London's Victorian concert venue has been utterly transformed, complete with six-tonne Japanese temple roof suspended above the ring.
It is here the wrestlers, known as rikishi, will perform their leg stomps to drive away evil spirits, and where they will clap to get the attention of the gods.
And above all this ancient ceremony, a giant, revolving LED screen which wouldn't look out of place at an American basketball game, offering the audience all the stats and replays they could want.
Sumo may be ancient, and may have strict rules governing every aspect of a rikishi's conduct, but it still exists in a modern world.
And that modern world is helping spread sumo far beyond Japan's borders.
It was a random video which first caught Sian Spencer's attention a couple of years ago. This was quickly followed by the discovery of dedicated YouTube channels for a couple of the sumo stables, where rikishi live and train, waking up early to practise, followed by a high protein stew called a chankonabe, and then an afternoon nap - all in the service of bulking up.
The London tournament was simply a once-in-a-lifetime, not-to-be-missed, opportunity to see it all in real life, the 35-year-old says.
Julia and her partner Cezar, who live in Edinburgh, discovered sumo through a more traditional route: a trip to Japan six years ago. We saw it as a very touristy activity, but we actually ended up loving the sport, says Julia, 34.
Going to Japan is almost the only way to see a top-flight sumo tournament. This week's event in London is only the second time the tournament has visited the city - the first time was in 1991 - while the last overseas trip was to Jakarta in 2013.
But even going to Japan isn't a guarantee of getting a seat. Last year was the first time in 24 years that all six of the bi-monthly, 15-day events had sold out in 28 years, Kyodo News reported - fueled by interest at home, and by the tourist boom which saw more than 36m foreigners visit in 2024.
So for many, the London tournament is the first time they have watched sumo in person - and it doesn't disapoint.
Caspar and his wife Megha Okhai had been among those lucky enough to get tickets when they visited Japan last year - only for them not to arrive in the post in time. It didn't stop them falling head over heels, however, and they have watched every basho this year. So when it came to the London Grand Sumo Tournament, they weren't taking chances.
I think we had four devices trying to book tickets, Caspar tells the BBC ahead of the event, displaying his sumo towels proudly - a must for diehard fans. We got front row seats, on the cushions.
Seeing all this ritual and ceremony that goes with sumo is quite special, fan Sian says. Now, seeing it in person, you feel like you are more part of it.
