Diaz had only arrived on Merseyside less than 48 hours previous, but was called upon as a second-half substitute as the Reds took on Cardiff in the FA Cup.
It came from a moment of sheer persistence from Diaz, who hounded a dithering Perry Ng on the touchline, won the ball and cut it back for his new team-mate to hammer home on the way to a 3-1 victory.
After the game, Diaz took to Instagram to take in a solid start, describing it as a “dream debut.”
“Dream debut,” he wrote.
“It’s incredible to be at Anfield and feel its atmosphere on the pitch. Great team match. Let’s go Reds!”
It was a bright debut from Diaz, who floated around the final third – at times on the left, at times up front, at times on the right – in a glimpse of how Klopp’s forward line could shape up in the weeks to come.
The manager praised his new No. 23 in his post-match press conference, and in particular the move that made it 2-0 on the afternoon.
“The goal he set up for Taki was absolutely incredible,” Klopp said. “High-press, counter-press, I love it!”
But there was also a moment that left him open-mouthed as Diaz challenged for a high ball with Cardiff centre-back Aden Flint, who landed on the winger’s knee and left him waving for treatment.
“He now has a bruise there, it’s red and a little bit open,” Klopp added.
“We all said ‘welcome to England’ and now he has his first assist and his first little scar.
“That’s absolutely OK. I don’t think it will be serious, maybe tomorrow he feels it more then we have to react to that. But it’s nothing serious.”