Ngumoha, who turns 17 later this month, shone again in pre-season to get fans wondering if he could be part of the first team this year.
The second youngest Liverpool player in a competitive game ever started this friendly on the left wing – and he caught the eye as he has done all summer.
The teenager scored in just the second minute as he ran onto a loose ball in his own half before racing forward and curling a fine effort in from 20 yards out.
Just three minutes later he nodded a Doak cross down for Darwin Nunez to convert from close range.
Liverpool fans were singing his name as Curtis Jones urged them to show their appreciation.
And he caused the La Liga side all kinds of problems with his dribbling and trickery.
The 16-year-old left to a standing ovation midway through the second half.
“He is such an excellent prospect,” said ex-Reds defender Gary Gillespie on LFC TV.
“The difficult is managing expectations but it’s hard to put a lid on it.”
Slot said: “Rio is showing things every time in pre-season.”
Ngumoha’s performance came on the back of an assist against AC Milan and goal against Yokohama F. Marinos in Asian friendlies.
He looks a fine talent, if raw, and will be hoping more first-team competitive games are on the way.
In January, Ngumoha became the youngest player to start a match for Liverpool – aged 16 years and 135 days old – in the 4-0 win over Accrington in the FA Cup.
But that was his only first-team appearance and he never made the bench for a Premier League game.
That could well change this season, especially with so many changes in the Liverpool front line.
The sad death of centre forward Diogo Jota in a car crash has been the main focus of Liverpool’s pre-season. There were tributes to him before and during the game at Anfield.
Winger Luis Diaz was sold to Bayern Munich and Nunez is a target for Saudi Pro League clubs.
An exit for Nunez would mean the Reds’ only really strong frontline options would be Salah, new signing Ekitike and Gakpo – giving a chance for somebody like Ngumoha to break through.
That is unless they managed to sign Newcastle striker Alexander Isak. An initial bid of £110m has been rejected.
“I’m not trying to rush because I’m still only young,” said Ngumoha last week.
“But at the same time, I just want to show the manager what I can do and not get too complacent. I just want to do bigger and better things for me and the club.”
Ngumoha is not actually a Liverpool academy product, having only joined Liverpool from Chelsea’s youth set-up last summer.
At the time Blues legend John Terry wrote “this boy is and will be a top player”.
He’s not looking wrong.
