I remember an old film (40s/50s?) possibly a western. During a fight scene (inside, possibly a bar), the actor swings a punch while saying Happy Birthday. He actually says "Happy" *swings punch* "birthday!". It was definitely an American film, possibly b&w, the actor was a largish guy at least in his 40s, possibly John Wayne? Ive tried searching via Google, Ive posted on a John Wayne fan site and a cowboy films site, to no avail.

not a Western ;but you are describing the plot of a John Wayne movie called 'Donovan's Reef' .
Donovan's Reef - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Donovan's_Reef)