Mishina and Gallyamov received 87.50 points from the judges for their performance.
The Russians broke the record of the Chinese duet Sui Wenjing - Han Cong (84.41 points), which was set at the 2022 Olympic Games in Beijing.
The achievement of the Russians will not be ratified, as the International Skating Union (ISU) does not take into account the results in national tournaments.
The second place in the short program was taken by Alexandra Boikova and Dmitry Kozlovsky (75.06), the third - Anna Moskaleva and Maxim Lozhkin (69.10).
Earlier, Elizaveta Tuktamysheva shared her impressions of participating in the First Channel Cup.