And yet, amid the mixed bag that even saw him sent off for headbutting Crystal Palace's Joachim Andersen on his Anfield league debut, Nunez's backers insisted he was a gem that merely needed polishing into something special.

Here, in the chaotic environment of Liverpool's meeting with Newcastle United at St James' Park, it was all hits and no misses as the 24-year-old was the architect of a truly remarkable turnaround with two late goals in a smash-and-grab 2-1 win for Jurgen Klopp's side.

Liverpool were a goal down when Nunez entered the fray with 13 minutes of normal time remaining, outplayed for long periods and outnumbered for more than an hour following captain Virgil van Dijk's red card for bringing down Alexander Isak three minutes after Anthony Gordon capitalised on Trent Alexander-Arnold's mistake to put Newcastle ahead.

It was strike one for Nunez four minutes after his introduction, taking Diogo Jota's pass in his stride to send a low, unerring finish past Newcastle keeper Nick Pope into the far corner.

Newcastle and St James' Park were collectively stunned as a victory that seemed theirs for the taking was in danger of being snatched away after their domination of a Liverpool side at a numerical disadvantage saw Miguel Almiron denied by keeper Alisson's miraculous first-half save, turning his powerful drive on to the woodwork with the score 1-0, the same player striking the post after break.

The emphatic nature of Nunez's goal, and Liverpool's growing threat, saw a stadium that had been thunderous in its support suddenly a bag of nerves, anxiety replacing anticipation.

If Newcastle's overriding emotion at throwing away a position of victory would have been disappointment, it was to get much worse in the third minute of the five added on.

Nunez was the destroyer once more, receiving Mohamed Salah's through ball before applying a slightly more deft but still powerful shot into the same corner of the net.

Newcastle were stunned. Liverpool elated. A contest that had simmered throughout came to the boil at exactly the right time for Nunez and his manager Klopp.

This was a tribute to Liverpool's character and ability to dig deep when all seemed lost. It was perhaps also a reflection of the block Eddie Howe and Newcastle seem to have when it comes to getting over the line against Klopp and Liverpool.

Howe's record against Klopp at Newcastle is played five, lost five, and this will surely be the most painful of all, even over and above a similar injury-time sucker punch at Anfield at the start of last season. Newcastle have not beaten Liverpool since a 2-0 win here in December 2015, shortly after Klopp came into Anfield and with Steve McClaren in the opposing technical area.

Klopp had cut an infuriated, frustrated figure for much of the game, raging at officialdom, his players and even seeming to give his own goalkeeping coach John Achterberg an ear-bashing at one point.

As seems normal when these two teams meet, the technical area was a hothouse even in what is supposedly meant to be a more civilised setting this season, Howe's assistant Jason Tindall touching his lips in a 'shush' gesture to Klopp when matters because overheated.

It came back to bite Tindall when the credits rolled on this one.

Liverpool rode their luck, Alexander-Arnold's mistake for Gordon's goal symptomatic of a very poor individual display, but they refused to buckle, taking advantage of Newcastle's carelessness to deliver that dramatic finale.

For Klopp, this will be affirmation of his belief that Liverpool are back on track after a mediocre season last time out which saw them trophyless and not even qualifying for the Champions League. No-one could say this was a classic victory, but it was one delivered in adversity against opponents who see themselves as rivals for a top-four place this term.

It was also their second successive win after being reduced to ten men after beating Bournemouth following Alex Mac Allister's subsequently rescinded red card.

Make no mistake, Klopp managed his in-game circumstances better than opposite number Howe managed his.

Klopp's substitutions were positive, even with ten men, and the impact was there to see in the shape of Nunez and Jota. Howe's replacement of goalscorer Gordon and the elegant, influential Sandro Tonali could only have been down to tired legs as there was no other good reason to remove them. Newcastle lost shape and momentum with their departure.

If Nunez really has honed his habit of erratic finishing, there is some firepower in this Liverpool team alongside Salah, Jota, Luis Diaz and Cody Gakpo.

For Newcastle, this was a brutal lesson after not finishing off an opponent when they seemingly had them at their mercy - Liverpool's hold on Howe and his team extended and perhaps playing on their mind after their failure to kill the game off.

Former Scotland international Pat Nevin, told BBC 5 Live Sport at St James' Park: "Newcastle could have wrapped it up, should have wrapped it up but Liverpool hung on and then got better and better. The changes Klopp made were brilliant. He threw on Nunez and Jota and what he hoped would happen happened.

"But with Newcastle it was about the mentality of knowing they can go and beat a team like Liverpool. They didn't know and that's the difference. Liverpool know they can come back from these positions."

Klopp insists Liverpool have "reloaded" after the disappointment of last season - and in those final minutes Newcastle were left reeling by Nunez's firepower.