Longstaff came on as a substitute in a 4-0 defeat for Newcastle United, handing the travelling fans something to shout about.
And they did just that, hailing Longstaff as 'one of their own' and signing that they'd run on the pitch if the local lad managed to get himself a goal.
That claim was nearly tested, too, with a chance late on for the player who tried to take advantage of a little moment of madness from Alisson.
He'd see his shot saved but the moment was held onto as a positive by Benitez after the game.
"I think it will be good and bad memories for him," said Benitez, according to the Chronicle. "Obviously his debut at Anfield and with a great atmosphere, but bad memories because obviously we lost the game.
"But he did well, he even could have scored a goal, and that was positive in terms of a young lad coming here and not being scared of trying to do something.
"Hopefully he can be an important player for us in the future."
It wasn't a great day for the Magpies but Longstaff's debut and ability to fit in can certainly be held up as a positive, particularly if he kicks on from here.
From that perspective, perhaps it was a good move from Benitez to find a way to get something from that game, even if it wasn't points this time.
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