Irony is "say one thing and the opposite thing happens" (or "the opposite of what is expected"). Most people misuse it.
Belt making an out was not the opposite of what was expected - he's not hitting anywhere near .500.
The NY Times stylebook, says:
The loose “use of irony and ironically, to mean an incongruous turn of events, is trite. Not every coincidence, curiosity, oddity and paradox is an irony, even loosely."