It has taken Darwin Núñez a year to make an impact at Liverpool, but he couldn't have timed it better. Two goals from the Uruguay forward as a late substitute at Newcastle United on Sunday turned defeat into victory for Jurgen Klopp's team and, maybe, finally showed us what all the fuss was about.

Since arriving in a club-record transfer from Benfica in the summer of 2022 in a deal that could eventually cost Liverpool 85 million, Núñez has blown hot and cold. He has shown glimpses of world-class ability, but more often than not, those brief flashes have been overshadowed by poor finishing, erratic decision-making and a short fuse that opponents have triggered to distract his focus and render him close to a liability at times.

But there has always been something there in Núñez. He is a rough diamond that will require time to be polished into the finished article, yet his ability to frustrate fans, teammates and Klopp alike has seen the 24-year-old go into this season with doubts over whether he can be the real deal for Liverpool.

Two crucial goals at St. James' Park, which secured a 2-1 win for Liverpool despite being reduced to ten players by a 28th-minute red card for captain Virgil van Dijk, will not banish those doubts for good, but the ruthless manner in which Núñez took his chances will have come as a huge relief to Klopp because his team needs Núñez to come good more than ever this season.

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"Núñez was a super performance," Klopp said. "He was obviously fired up from not starting. It's clear he's not happy. It's early in the season, we need to find stability and results, but he will play, there's no doubt about that.

"But he has scored two goals and he can't get the smile off his face."

Having been signed as part of Liverpool's plan for a future without Sadio Mané, Roberto Firmino and Mohamed Salah, Núñez endured a difficult first season at Anfield. He scored just nine Premier League goals, and six more in other competitions, so his end-of-year report card will have been a five out of ten at best.

But with Firmino leaving the club at the end of his contract over the summer -- 12 months after Mané moved to Bayern Munich -- only Salah remains of the club's Champions League- and Premier League-winning front three, so the time has come for Núñez to deliver. He still hasn't started a game this season, with Klopp using him from the substitutes' bench in each of Liverpool's three fixtures so far, and that points to the Liverpool manager still being unsure how to get the best from his most expensive signing.

Núñez's first chance at Newcastle highlighted just why Klopp harbours doubts. Racing onto a through-ball, Núñez fluffed his control, and within seconds, Harvey Barnes almost put Newcastle 2-0 ahead at the other end.

But the major positive with Núñez is that, despite the mistakes and missed chances, he has the ability to blank out the negatives and go again. And when he scored the equaliser from an almost identical chance to the one he had messed up moments earlier, it was with a clinical shot across the face of goal that only the most in-form striker would usually attempt.

Finding a way to make Núñez take those chances consistently is Klopp's challenge, but it is a challenge he will persevere with. The player has such attributes with his pace, movement and finishing (when it comes off) that Liverpool know they have a forward who could score between 20 and 30 goals a season eventually.

When Núñez scored the winner, after being released by Salah's pass, it was another cool finish beyond goalkeeper Nick Pope that made a mockery of his reputation as a player who misses more than he scores. The issue with Núñez is that he scores the tough chances and struggles with the seemingly easy ones, but fixing that flaw should be possible with time on the training pitch.

That Núñez was even able to rescue and win this game for Liverpool is a testament to the resolve within Klopp's team.

They were overrun by Newcastle for long periods, but after losing Van Dijk following a reckless foul on Alexander Isak, somehow found a way to resist the home side long enough to stay in the game. Goalkeeper Alisson Becker made crucial saves, with one from Miguel Almirón preventing Newcastle from going in 2-0 ahead at half-time, and the home side couldn't find a way to score the second and kill the game.

"We should have put the game to bed and that is probably the thing we are all kicking ourselves with," Newcastle manager Edde Howe said. "We had a lot of chances and goalmouth action. Their goalkeeper made one of the best saves that I have seen live from Almirón and it just wasn't to be for us.

"The moments and chances were there right until the end but we lacked the killer instinct."

It was Núñez who displayed that killer instinct, however, and his contribution won the game for Liverpool. This was his biggest moment in a Liverpool shirt, the day when he truly made a difference when the pressure was on.

Núñez now needs to make it the norm rather than a rare highlight.