XABI ALONSO had seen it many times before – a visiting team getting absolutely torn apart on a European night in front of the Kop.

Unfortunately for the Bayer Leverkusen manager, on his return to his former home of Anfield, there was nothing he could do to stop his team from suffering a ferocious second half mauling.

Luis Diaz celebrates in front of the Liverpool fans

Liverpool denied Xabi Alonso a rosy return to Anfield in a 4-0 win

Alonso’s Bayer Leverkusen side were swept away in the second half

Alonso’s side, who won the German League and Cup double last season, arrived on Merseyside with a swagger and were giving a pretty decent account of themselves.

Yet in the space of three minutes, it all went horribly wrong. And then, it got even worse.

Luis Diaz scored a terrific opening goal and with the home crowd baying – even though it was Alonso’s – Cody Gakpo headed the second even though it was initially ruled out by VAR.

Diaz then got his second, and then third, for his first Liverpool hat-trick. This capped a brilliant second half, the best of Arne Slot’s short reign.

Liverpool played with so much speed and intensity and they were clinical when it really mattered, against a really decent defence.

This will have been really tough viewing for Alonso. He could have had the Liverpool job if he wanted it and maybe, one day, he will get the gig on Merseyside.

But for now, Liverpool will be absolutely delighted over appointing Slot. It is now 14 wins, one draw and a defeat.

Liverpool struggled against Brighton on Saturday but after conceding, hit back with two goals in as many minutes.

Jeremie Frimpong was denied an opening goal for Leverkusen in the first half

His goal was ruled out for a handball in the build-up

Luis Diaz netted a delightful chip to score the opener for Liverpool

And they used a similar type of whirlwind performance to knock the stuffing out of Leverkusen who had been brilliantly organised at the back but were then exposed horribly.

Slot already seems to be getting the big calls right. He made just two changes from the Brighton game and they were Luiz and Curtis Jones, who combined brilliantly for the opening goal.

Maybe Alonso should have known it was going to be one of those nights.

Leverkusen had more of the ball – 58 per possession in the first half – and they even created the odd chance.

Former Arsenal midfielder Granit Xhaka hammered a thunderbolt which smacked Virgil van Dijk flush in the face and unsurprisingly, floored the Reds captain.

Dutch ref Danny Makkelie stopped play for his fellow countryman.

Leverkusen striker Victor Boniface was a handful although needed treatment after he ran into the advertising boards in front of the Kop after firing a shot into the side netting.

Equally, Alonso’s team defended well with their back five when Liverpool had the ball and gave them very few opportunities.

Gakpo should also have done better rather than fire a shot straight at keeper Lukas Hradecky, although that came after a big scare for the home team.

Jeremie Frimpong thought he had put Leverkusen ahead with a cracking finish but the linesman correctly spotted a handball – even though it was accidental – as the Dutchman got past Kostas Tsimikas before beating Caoimhin Kelleher with his shot.

Liverpool still struggled in the second half and when a golden chance did fall to Mo Salah, it fell on his right foot and he made a complete mess of the opportunity.

It needed something special and Curtis Jones delivered it with the quality pass and Diaz produced an absolutely sublime finish for the first goal in the 61 st minute.

Slot will have been delighted with that combination, given his tactical decision before kick off.

Gakpo thought his header from Salah’s brilliant cross had been ruled out for offside but after a VAR check, it was given.

Cody Gakpo netted the second for Liverpool

The Dutchman nodded home a great header at the back post

Additionally, Diaz had too much strength for a defender after a Salah cross, and he scored from close range.

Then he clinched the match ball with a close-range hat-trick in injury time.

Liverpool will most likely finish in the top eight of the Champions League, which means they will not be able to advance to the February play-off round.

Additionally, avoiding a few European games might be quite important given how many games Slot’s team may wind up playing this year.

Luis Diaz netted a hattrick to continue his hot form and see off Leverkusen in style

Arne Slot is making things look easy on Merseyside