Pini Zahavi, football's first and only super-agent.

Is the phrase first and only an idiomatic expression? Does it mean that he was both FIRST and ONLY or just FIRST???

He was the first, and there has NOT been anyone else since then.
Another idiomatic expression is "the one and only...".
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PhilipAnother idiomatic expression is "the one and only...".
Yes, but this one is clear because "one" and "only" mean actually the same thing, while "first" and "only" may mean two different things.

Zahavi could be the first football agent, but is he really the only one? There are no other football agents except him?