If the nature of their rivalry with Brazil means many an Argentinian will not gush about Rio, Alexis Mac Allister was a happy exception. “Rio was amazing,” he said, and if he was talking about Rio Ngumoha rather than Rio de Janeiro, the sentiments were shared.

The Kop borrowed a chant from other historic enemies, Manchester United, to salute the 18-year-old as he became the youngest Liverpool player to assist a goal in the Champions League or to make two in a game since Michael Owen in 1998. Which, to put it another way, was about a decade before his birth.

Liverpool’s comeback win against Villarreal had the feel of another night when Ngumoha took a sizeable step forward. Although, given the speed at which he surged, his acceleration may have taken him further than that. Sometimes teenage talents have technique before they have the physique but it was notable how much speed and power Ngumoha showed on the burst to set up Mac Allister’s second goal.

“The man came tight to me and the ball came, my first touch was direct and then I’m able to run at pace. Macca, good finish,” said Ngumoha. Andoni Iraola was quick to point out that the winger could have gone down and perhaps got a penalty. The thought did not seem to enter Ngumoha’s mind.

He likes running at defenders, but also getting past them. “Whenever I get the ball and there’s an opportunity to go one-v-one or two-v-one sometimes, by all means I’ll do it,” he added. “I believe in myself to do it.”

Liverpool have believed in Ngumoha for a while, but also realised they had to show some patience. Arne Slot was booed when he took the youngster off against Chelsea in May but was always conscious of how many minutes to give a player adjusting to first-team football. There are other reasons why his introduction to the side has been gradual. “He struggled defensively in the first half,” said Iraola on Tuesday. “The second half was much better.” Mac Allister also pointed out the rookie’s work off the ball.

Iraola added: “Today he didn’t have an easy game also because they were demanding him defensively and their left-back was attacking a lot.” Ngumoha was able to turn the tables and Iraola said: “There was a moment offensively where he was very difficult to stop. If we can put Rio in situations one-v-one, he makes plays, he produces things. The assist for Alexis is a lovely play. Also, endurance-wise he is able to play more and more minutes. We were pushing him a little bit.”

The sense is that Ngumoha is both a quick learner and a willing one. “I am very happy with his attitude because he tries to improve the things we think he needs to improve,” said Iraola. “He is eager to add more things to his game.”

One is the capacity to play on the right. The right winger who used to star on Merseyside on Champions League nights was Mohamed Salah. On Tuesday, it was Ngumoha. Yet after Liverpool missed out on the signing of Yan Diomande, they ended the transfer window with four wingers who prefer to play on the left. Since then, it has seemed they are taking it in turns to impress on their less-favoured flank. Cody Gakpo has delivered from terrific crosses from the right. Victor Munoz has scored one goal operating as a right winger and another as an auxiliary right-back. Ngumoha illuminated a Champions League night at Anfield when he was not even operating in his preferred position.

“He has changed the sides a lot. He has played a lot on the right,” said Iraola, who wants wingers who he can use on either side. “Lately he is feeling so comfortable now and is having some shots with the left foot. He hasn’t scored yet but he is getting there and if he adds small things to his game it will put him in an even better position.”

Goalscoring is an area that offers scope for improvement. Ngumoha’s tally stands at two goals in 39 games for Liverpool, even if only 15 were starts and he has only once completed 90 minutes. Liverpool’s other three wingers have seven goals between them this season. He only has one since last August’s 100th-minute winner at Newcastle.

“The good thing with Rio is he is still 18,” Iraola said. “He is not the full package. He can add things, fortunately for us. Hopefully he can continue in the same way. He’s not always going to be like this. He will have ups and downs in the process. But I’m happy because attitude-wise I think he’s in a great place.”

And Liverpool, lamentable in the first half-hour against Villarreal, triumphant by the end, were in a rather better place after he served Europe notice of his talent.