Comedic in example sentence
Matthau seems to had been born to play Willie Clark (of course, Oscar moreso in the Odd Couple), and with all of the little idiosyncracies and mannerisms that Matthau crams into the character (the line where he is arguing that he is with it since he lives in the city whereas Lewis lives in the country that Lewis is "out of touch" is the quintessential example of this) make this one of the best performances I've ever seen of any actor in any role, be it comedic or drama or whatever else.