You know how it is, we see it in sports all the time when one team or individual is just exponentially better than the competition and totally crushes them. It can be a bit embarrassing and tough to watch.
It happens in comics too and here are a handful of occasions that I have thought of. Anyone want to comment or add another one?
Superman vs. ToymanI'm not sure who ever thought this was a good idea. Not that there's anything wrong with playing with toys

but how are you expecting to use a couple of Barbies and Thomas the Tank Engine to defeat a super strong, nearly invulnerable alien who can fly, has laser eyes, hurricane strength breath, super speed, super hypnosis and who knows what else?
Hulk vs BoomerangSee above. Seriously, a dude throwing sticks is going toe-to-toe with a green goliath capable of literally holding up an entire mountain range? (See the original Secret Wars)

American Eagle vs. BullseyeDon't know about you but this was a seriously satisfying read for me. I mean Bullseye is definitely one of those villains that you love to hate and seeing him get his behind handed to him like that was fun!
Galactus vs. UltronSpeaking of Secret Wars...

When Ultron is on the wrong end of a lopsided defeat then you know the other guy is serious. Galactus just "Snuffed him like a candle".
Batman vs. Guy GardnerBwa-Ha-Ha-Ha-ha! A source of amusement for several years was the Dark Knight clocking the arrogance right out of GG with a single punch.
Ozymandias vs. The WatchmenI don't think I have ever seen such a complete bamboozling of heroes by a villain ever. In any medium. He was so far ahead of them it was like he was calculating the square root of pi cubed while they were still trying to figure out 2+2.

Plus he croaked two of them, Comedian and Rorschach. (Yes, technically Dr, M killed Rorschach but it was caused by Ozy)
Anybody vs. The Circus of CrimeThe list of heroes who have
not beaten these imbeciles is shorter than the list of heroes who
have beaten them. What, Power Pack didn't want any of that?

Seriously, what could be more intimidating than a larcenous traveling circus composed of a hypnotist, Pennywise, a couple of acrobats, a guy who's power is shooting himself out of a cannon and a sexy snake charmer?

I've got more but why should I have all the fun?
Whatcha got?
Hardships often prepare ordinary people for an extraordinary destiny - C.S. Lewis