Second-placed Young You becomes 11th woman to land the jump in international competition.
Triple Axels were the order of the day during a scintillating women's short program at Skate Canada as Rika Kihira took the lead, with second-placed Young You landing the jump for the first time in international competition.
Japanese skater Kihira received a standing ovation from the Prospera Place crowd in Kelowna, British Colombia, after landing her trademark three-and-a-half rotation jump cleanly in a solid program that scored a season-high 81.35.
The 17-year-old now heads an intensely-competitive women's field ahead of Saturday's free skate but says she is focused on herself rather than her competition.
I want to be positive by only focusing on perfecting my performance. - Rika Kihira
"I want to be positive by only focusing on perfecting my performance and not paying attention to other skaters," said Kihira, who admitted she suffered from nerves.
"I think the result of my performance at the short program was positive for me, so I can perform in the free program with confidence. But I should also think about what is missing and what else I should do in the free program so that I can perform with confidence."
Kihira was not the only skater to land the notoriously difficult triple Axel, as South Korea's Young You became just the 11th woman to land the jump in international competition.
You, 15, whose idol is Yuna Kim, said she was "honoured" to land the jump after training it for three years.
"I actually thought I wouldn’t because right before I was really nervous," said You. "But I tried to think like I did it in practice normally, think more calm, and I think it was better for me.
"Some days, because it doesn’t work well, I feel like, ‘should I do it?’ It feels like it keeps me down. I have no confidence.
"But today, I finally landed it... I feel really honoured."
Kihira and You train with the same coach, Mie Hamada, and the South Korean says she aspires to jump the triple Axel as well as the Japanese skater.
I really want to [jump] like her triple Axel but it means I need more practice! - Young You on Rika Kihira
"Rika is way better than me and she's way better at the triple Axel than me," said You.
"I train with her and she's a really amazing skater. I really want to [jump] like her triple Axel but it means I need more practice!"
You's clean program scored 78.22, placing her second ahead of the free, where she has another triple Axel planned.
But third-placed Alexandra Trusova is in hot pursuit of the two leaders - and has an astonishing four quadruple jumps planned in her free program which could see her vault into top spot on the podium.
Trusova, making her senior Grand Prix debut in Canada, also skated clean, scoring 74.40.
“I waited for a long time to compete at senior level, so nothing has affected me today," said Trusova, who is planning a quad Salchow, a quad Lutz and two quad toe loops, in different combinations, in the free skate.
"I am calm and I want to skate clean tomorrow.”
Asked about her anticipated quad jumps, she smiled, adding: "You will see everything tomorrow."
The Russian, who also confirmed she is working on adding the triple Axel to her already loaded repertoire, lamented that current rules mean she cannot perform quad jumps in the short program, saying: "It's a pity."
There was disappointment for Olympic silver medallist Evgenia Medvedeva of Russia, who stepped out of her double Axel and fell on her triple Lutz, leaving her down in sixth place.
In such a strong field, Medvedeva faces a tough challenge to climb the table on Saturday.
Having taken the top spot on the podium at their opening Grand Prix of the season in Las Vegas, they didn't have much breathing space before another outing in Kelowna.
But the Americans seemed none-the-worse for the quick turnaround, posting a score of 83.12 to take the lead in Canada.
Home favourites Piper Gilles and Paul Poirier weren't far behind, with their crowd-pleasing 'Mack and Mabel' program scoring 82.58 to set up an exciting free dance final on Saturday.
It was a personal best for the Canadian duo, prompting a huge response from the home crowd directly before the Americans took the ice, but Donohue said it didn't affect their performance.
"When we’re on the ice, we’re in a bubble," he said. "We know they’re gonna have a score. They’re an amazing team and are going to have a high score.
"We’re not out there trying to beat them, we’re out there trying to perform to our capability and to do what we’re trained to do."
Hubbell added that having back-to-back Grand Prix was not causing them problems.
"It is a quick turnaround but the same as when we take a two-day weekend during our training week. It feels about the same," she said.
"We feel ready and prepared for this competition. I guess we are used to this schedule."
Kaitlin Hawayek and Jean-Luc Baker, also of the United States, completed the top three.
Olympic Channel are on the ground in Kelowna bringing you news, reaction and content from behind the scenes. Follow @OlympicChannel on social media.