I never ran into that problem in 3E/3.5E, but it did happen sometimes in older editions with the unbalanced XP progression (My human ranger 6 had the same total XP as the Elf Fighter 5/Wizard 4)
Try any single monster encounter where the monster gets hit by Blinding Spittle or Glitterdust.
Or any dragon encounter where dragon gets hit with Shivering Touch.
Or any large group encounter where they get webbed and die.
Any Golem encounter where the golem got buried under mounds of druid summons and beaten to death.
Any encounter ever where the words "time stop" were uttered.
Etc.
Quite easy for a Wizard to trivialize many encounters. Fighters... not so much. They tended to whack things for pretty good damage, but they never really shined, even in combat. Outside of combat, welp.