LogFAQs > #974063329

Hulk is one of the characters most nerfed from the comics because they need to keep him from being drastically overpowered compared to the people around him. He usually loses for narrative reasons (like being knocked out by a Hulkbuster punch in Age of Ultron because the writers had no other way to stop his rampage without him being unusable for the rest of the movie)

There's the implication that before meeting Thor in Ragnarok, he was undefeated in gladiatorial combat, but of course that's all off-screen so it doesn't really count