DISMANTLING MYTHS: Can a bike with 26 'wheels be faster than one with 27.5' wheels?

Recently I came across a completely unusual situation riding a bike. I usually complete the route that goes from the town of Cedillo de Condado to Toledo. It is about 32 km. I usually complete it in 1:30 h. approximately (1:25 if I decide to wax).
In one of my last outings I have broken my personal record by covering this distance in a time of 1 hour and 22 minutes, a record that for me is quite good. The strange thing is the circumstances in which I achieved this "personal record":
lack of physical background (quarantine, you know)
Lack of motivation (usually to your trip for pleasure but this time I had to do it because I did not have my car available and I needed transportation to go to work. As it was not a planned outing, the truth gave me a bit of a downfall)
the most important, THE BIKE. My regular bicycle was undergoing repairs, so I had to take my wife's bicycle and eat a Monty that they gave me many years ago with yogurt caps and that throughout these years has not had any type of technical improvement, cleaning or greased. Also, and it's what I don't understand, it's a pretty heavy bike with 26-inch wheels.
Taking everything into account, how is it possible that I had a better time than when I go out with my usual bike? It is not a cucumber, although I have it quite battered and very up-to-date in components.
That's why I decided to do this experiment in which I would go out with the Monty again but this time ON FIRE to try to make the best time possible ... will I get my best mark?