Iker Muniain put the La Liga side 1-0 up in the first leg of the Champions League third qualifying round tie, but the Argentine salvaged a draw with his 68th minute strike.
The draw gives Athletic the advantage heading into the second leg at San Mames and Benitez revealed Higuain and the rest of the squad were disappointed with the result.
He said: "Higuain is angry, like everyone, as we expected a tough game and to win it. At least it means he’ll put even more determination and anger into the second leg."
Napoli was undone by the intensity of Ernesto Valverde's side and Benitez admitted as much after the game, but insisted he still saw the result as a positive one.
“Athletic Bilbao are an intense side who work hard, but at the start we had two or three great scoring opportunities. We didn’t, and with their intensity Athletic took control," he added. "Considering the way the game went, we can consider our reaction positive and must begin again from that.
“Athletic will certainly go out there to win (the second leg), which means they want to score and so do we. I have confidence, of course it won’t be easy, but today we proved with five or six scoring opportunities that we can hurt them.”
Lorenzo Insigne endured a night to forget and was booed by his own supporters after being subsituted in the second period, to which he responded with a sarcastic gesture, though Benitez was quick to play down the incident.
"Insigne is Neapolitan, wants to impress his people and it’s not always easy to keep control of those intense emotions at this level.”