Yuzuru Hanyu and Nathan Chen both fell in practice ahead of the 2019 Grand Prix of Figure Skating Final.
But of perhaps greater significance to the duel between the sport's big two was the double Olympic champion landing a quad Lutz despite it not being in his planned program content.
Hanyu sustained an ankle injury attempting that element in training at the 2017 NHK Trophy which ruled him out of action until PyeongChang 2018 where he successfully defended his Olympic title.
It means the Japanese, who turns 25 on Saturday, has four different quad jumps at his disposal for the free skate.
Hanyu will want to improve on his quad loop having fallen twice attempting the jump in practice.
One of those came at the start of his run through of his free skate 'Origin', although the rest of his jumps - including quad toe loops, quad Salchows and triple Axels - were on point.
For a change, coach Brian Orser was not at rinkside as he was coaching "Future Olympians" at Toronto Cricket Club.
But he is expected to be in Turin in time for tomorrow's short program, starting at 21:10 local time, as Hanyu and Chen meet for the first time since the American retained his world title in Saitama in March.
Defending Grand Prix Final champion Chen also hit the deck in his free skate run through.
He landed the quad flip at the start of his skate to music from the Elton John biopic Rocketman, but then came unstuck on a triple Axel.
The American has four quads planned for his free skate, the same number as Hanyu, although he did attempt six at PyeongChang where he posted the highest score after a disappointing short program.
Jin Boyang is one of the leading contenders for bronze in his first Grand Prix Final for four years, but the Chinese did not attempt any jumps in his run through.
Kevin Aymoz is skating in his first Grand Prix Final.
The Frenchman was happy with his training session and delighted to be in Turin.
He told Olympic Channel, "I was good on my feet, good on my blades, good on my skates, it was just cool to skate.
"For me, it's new so I'm going to take the experience this season and just do my best. I'm just happy to be here. When I was young I never imagined I would be here."
The 22-year-old has won plenty of fans for his artistic interpretation of the music, particularly in his short program routine to Prince's 'The Question of U'.
He's starting to get used to competing with the best, and gives himself a pep talk every time he is about to perform:
"I know I'm always saying the same thing but... they're saying my name and I'm saying like, 'You are there because you love it. So go.'"
Russian team 'no show' at ladies' practice
Bradie Tennell and Rika Kihira were the only two women to take part in practice for the ladies' singles.
That's because the four Russians in the field - Alexandra Trusova, Anna Shcherbakova, Alena Kostornaia and reigning world and Olympic champion Alina Zagitova - had yet to arrive in Turin.
ISU press attaché Tatjana Flade told Sport24.ru that the quartet, all trained in Moscow by Eteri Tutberidze, spent more time preparing at home before flying out this afternoon with the short program not taking place until Friday.
The three first-season seniors look to be fighting it out for victory in Italy between themselves after sweeping all six Grand Prix events.
While twice world junior champion Trusova is the best known of the trio thanks to her quad-jumping exploits, Shcherbakova beat her by 0.07 points to take the Russian national title last December.
Shcherbakova also has quad jumps in her armoury and told Olympic Channel that performing them "feels like flying".
Defending Grand Prix Final champion Kihira landed a triple Axel in a clean short program run through while Tennell, who was in full costume, was not quite foot-perfect as she practised her free skate.
Kihira has a quad Salchow in her planned free skate program as she attempts to close the gap to the three young Russians in their first senior seasons.
The 17-year-old attempted it in practice without success, but may try it again in practice on Thursday.
The pair had to make the draw for the absent Russians with Tennell, who will skate fifth in the short program, speaking to Olympic Channel afterwards.
The team bronze medallist from PyeongChang 2018 said, "I am super-excited to be here. It was a really tough Grand Prix series in addition to me also not having very much time to prepare so I'm very proud that I made it here.
"And I'm really just looking forward to skating in this arena. I remember watching the Olympics on TV when I was eight years old here so it's very cool for me to be here in this building. And I really just want to enjoy the experience."
Papadakis and Cizeron bid to regain crown
World champions Gabriella Papadakis and Guillaume Cizeron are seeking to continue their ice dance dominance.
Having missed last year's event due to a back injury for Cizeron, the French duo have been peerless ever since and rewrote the record books at the NHK Trophy a fortnight ago.
They ran through their 1980s-inspired Fame short program with new costumes - the main change being Cizeron's bright green top instead of the open-neck pink number from earlier in the season.
Piper Gilles and Paul Poirier are competing in their first Grand Prix Final for five years.
The Canadians won Skate Canada and were second behind world silver medallists Victoria Sinitsina and Nikita Katsalapov at the Rostelecom Cup.
Gilles' labradoodle dog Scout hasn't made the trip to Turin, but the pair are looking forward to trying to better their fifth place from 2014-15.
The pairs skaters were the last on the ice with Aleksandra Boikova and Dmitrii Koslovskii impressing in their session.
The Russians boast the highest total of the season, achieved in their victory at the Rostelecom Cup, and look set to duel with world champions Sui Wenjing and Han Cong for gold in Turin.
The Chinese are unbeaten since taking silver at PyeongChang 2018 behind Aljona Savchenko and Bruno Massot.
Like Boikov and Koslovskii, Sui and Han won both their assignments in this season's Grand Prix series.
Juniors get set for big occasion
The first big name on the ice on Wednesday was US national champion Alysa Liu in Junior Ladies practice.
The 14-year-old has a triple Axel-triple toe loop combination planned for the start of her short program.
And her free skate looks set to open with a bang - a triple Axel-double toe loop combo followed a quad Lutz-triple toe loop and then another quad Lutz!
That said, Liu has some work to do if she is to come out on top with Russians Kamila Valieva, another Tutberidze pupil, and Ksenia Sinitsyna both outscoring her in Junior Grand Prix events this season.
The junior men were on the ice early with Japan double-handed in the form of Shun Sato and Yuma Kagiyama.
Perhaps reflecting the debate among figure skating fans, Sato says he's been inspired by Yuzuru Hanyu with Kagiyama citing Nathan Chen as his role model.
When is the Grand Prix final?
Thursday 5 December
15:30 Junior Men Short Program
16:35 Junior Pairs Short Program
17:50 Junior Ladies Short Program
19:50 Pairs Short Program
21:10 Men Short Program
Friday 6 December
15:00 Junior Ice Dance Rhythm Dance
16:20 Junior Ladies Free Skate
18:30 Ice Dance Rhythm Dance
19:50 Ladies Short Program
20:55 Pairs Free Skate
Saturday 7 December
13:00 Men Free Skate
14:20 Junior Pairs Free Skate
15:45 Junior Men Free Skate
18:00 Junior Ice Dance Free Dance
19:25 Ice Dance Free Dance
20:55 Ladies Free Skate