Roy Curtis: Alvarez and Man City bring the sword down on Liverpool’s miserable season

The Argentine, promoted to the starting line-up because of the master predator’s groin injury, unsheathed his blade and immediately showcased his own eloquent cutting edge.

Up in his private box, Haaland celebrated his understudy’s dazzling masterclass by bouncing around like an adrenaline-charged teenager in a summer music festival mosh pit.

The 40-goal striker’s giddiness, as much as the haunted, hollowed-out look of so many of those in red, announced this as a landmark milestone on the season’s journey.

Alvarez ruptured Liverpool’s spirit with a devastating, swashbuckling, high-energy shift, one that may have washed any remaining colour out of Klopp’s ambitions for this campaign.

The broken Anfield troops resemble a team thrashing around in a cellar of nostalgia, futilely searching for the old magic.

Their second-half capitulation was that of a team who are running on empty.

Now 22 points adrift of the team they had gone toe to toe with for the previous four seasons, their Champions League hopes are hanging by a thread after 90 minutes that advanced into the territory of humiliation.

Midfield was again a wasteland of invention, and Klopp’s team look like an ageing side withering on the vine.

City are operating at the opposite end of the bandwidth, toying with Liverpool here, reducing what was so recently a contest of equals to a tortuous watch for the travelling supporters.

Jolted into action by an early Mo Salah goal, the champions were irresistible, combining artistry and cutting edge, announcing to Arsenal that they will not cede their crown without a titanic struggle.

Jack Grealish, his performances increasingly matching his £100m price tag, his dribbling trumped only by his work-rate provided a reviving heartbeat after Salah’s beautiful finish.

Grealish was magnificent, tormenting Trent Alexander-Arnold with his dancing feet and sense of adventure, before completing the rout with the fourth goal.

He hardly looked like a player who by, his own admission, had felt sick pre-match and spent the morning in the bathroom,

The sugar rush of the one-time Ireland U-21 international’s finest afternoon in blue added to the euphoric mood in the stands.

Kevin De Bruyne, responding to rare, recent criticism from Guardiola, delivered one of those untouchable afternoons when he looks in a different class to even the best of his peers.

Like Grealish, the cerebral Belgian iced a special performance with a goal, his seventh of the season.

Riyad Mahrez flashed that rapier like left-foot as City looked as rampant as at any time in the star-spangled Guardiola era.

Alvarez, though, was the fire-starter, bagging the equaliser and playing a central role as the two quickfire second-half nails were hammered into Liverpool’s coffin.

Stepping into the biggest shoes in the Premier League, those of record-shattering Haaland, his performance emphasised that here is a 23-year-old World Cup winner.

Alvarez has thrived on limited opportunity, his industry and attitude impressing Guardiola, his finishing tormenting opponents.

Here, bagging his 13th goal, Haaland’s deputy laid down the law in the manner of a veteran sheriff.

On a potentially defining weekend, Salah drew first blood.

If he has not been at his absolute best this season, the Egyptian, when presented with a chance, continues to wear his conviction like a bulletproof vest.

His gorgeously struck 24th goal of the season – after poor City positional play allowed Diogo Jota to make a killing forward thrust – propelled him ahead of Michael Owen to become Liverpool’s leading away scorer in the Premier League.

But any feeling that it would provide Klopp with an urgently required stimulus package for their top-four pursuit was quickly wiped away.

City’s threat had been palpable before the goal, the movement of De Bruyne and Grealish bordering on artistic, Mahrez twice singeing Alisson’s woodwork with that educated left foot.

Grealish was a difference maker.

One moment he was making a lung-busting, 80-yard defensive run to prevent Salah from teeing up Jota for a second; a few seconds later he was delivering an assist for Alvarez to emphatically finish a sweeping, sumptuous City move.

Fifty seconds into the second half, the home side were ahead.

De Bruyne batted a gorgeous, curling cross from Mahrez to the net after a sensational crossfield pass from Alvarez.

The Argentine was involved three-times in the build-up to City’s third, Ikay Gundogan cleverly finishing after the rampant striker’s shot was blocked by Alexander Arnold.

Liverpool’s season has been a turbulent roller-coaster ride of maddening inconsistency.

Landmark slaughters of Manchester United and Bournemouth were hardly the performances of a time-expired force, but those wins amounted to pyrotechnic outliers for a side that is sagging like a condemned tenement.

Here they resembled a team devoured by age. The grind of the unforgiving years has stolen their energy, momentum and their devil.

Had Koppites been told last summer that they would arrive at this fixture holding a 14-6 aggregate advantage from five games (including Community Shield and cup competitions) with the twin Manchester giants, they might reasonably have anticipated a 20th title.

Instead, this has been a year to lay a wreath for, one ransacked by staleness and underachievement – and now reduced to a frantic pursuit of the last Champions League slot.

The contrast with those Klopp years when they sailed on currents of air has been stark.

For four coruscating seasons before this one, City and Liverpool had gone toe to toe at centre ring, two skilled heavyweights trading concussive, immaculately crafted blows.

Here, only the prizefighter in the blue corner could boast a knockout blow.

And when it was unleashed, it left the outclassed opponent in red on the canvas, seeing stars, and facing a future shrouded in uncertainty.