A very young Irina and Alexei winning their first World title at their first attempt; the first of what would be 10 for her. They leave out a lift rather obviously half way through - probably minimising the impact of altitude? - but their speed and level of difficulty really were like a revolution in the sport of pair skating and their win was unanimous with the judges.
If you watch this and then compare it to 1977 Worlds or 1978 Europeans when Rodnina was at her absolute best, you can see the massive improvements she made in her skating throughout the decade. It's not as if she stayed in the same place. But this was a definite changing of the guard, backing up their surprise European title in Garmisch (they were only second at the USSR Nationals in 1969) and handily beating both the Protopopov's and the 1969 USSR champions, Tamara Moskvina and Alexei Mishin.
The commentator is 1949 European Champion and the first lady commentator, Dr Eva Pawlik of Austria.