Well I wouldn’t say Vader outclassed him… only inasmuch as Vader kind of “cheated”. I mean, you’re swordfighting and also hitting the guy in the back of the head with toasters and stuff at the same time.
While you could say there’s no “rules”, if we’re supposed to believe Obi Wan’s speech in New Hope describing a nobler time and a gentleman’s weapon and all that, Vader could be argued to be using bad form here.
Course, with the prequels, Lucas crapped all over Obi-Wan’s description of the era of light sabers and Jedi, but hey.
It is an interesting pt. to say that there’s a great contrast in Luke getting pwned after you’ve seen his training montage. I mean, if the movie had been made 8 yrs later, the whole Dagobah thing would have had a Bob Seger track behind it and end with Luke knocking the sword out of Yoda’s hand to show how much he’d learned… and then after the big training montage Luke goes off to face his Clubber Lang /Cobra Kai and… loses miserably and gets dismembered.