UEFA Champions League Liverpool 4 Bayer Leverkusen 0 Full time

Xabi Alonso's emotional return to Anfield ended in heavy defeat with Luis Diaz scoring a hat-trick as Liverpool maintained their flawless Champions League record by overpowering Bayer Leverkusen.

Alonso remains a hugely popular figure at Liverpool after winning the Champions League in 2005 and was heavily touted to succeed Jurgen Klopp this summer until he decided to stay in Germany.

Arne Slot was eventually appointed and his outstanding start continued as Liverpool once again recovered from a sluggish first half to overwhelm Leverkusen, who had controlled them comfortably before the break.

Luis Diaz broke the deadlock after 61 minutes with a deft lofted finish over keeper Lukas Hradecky from Curtis Jones' pass, Cody Gakpo adding the second two minutes later from Mohamed Salah's cross - the goal initially ruled out for offside before being given after a Video Assistant Referee review.

Diaz was on target again with a close-range finish seven minutes from time to give the scoreline an emphatic appearance that did not seem likely in the low-key, uneventful first period.

And there was still time for the Colombian to smash home a rebound to take home the match ball after substitute Darwin Nunez had his effort blocked, completing his first hat-trick for Liverpool.

The win means Liverpool stay at the top of the new Champions League format standings with a maximum 12 points from four games.

Liverpool surge destroys Alonso's dream

Liverpool turned on another second-half show of power as Alonso's hopes of producing a Champions League shock were blown away against his former club.

Slot's side have been slow starters this season, most recently against Brighton on Saturday when they turned around a 1-0 deficit to win 2-1, but once they clicked into gear after a lifeless first 45 minutes, Leverkusen could not live with them.

In the early phases, Liverpool were frustrated as Bayer played with patience and control, slowing the tempo, never giving Slot's side any chance to build up a head of steam.

It was all change after the break as Liverpool, kicking towards the Kop, knocked Bayer out of of their previously measured stride, Diaz's composed finish opening the floodgates as the Bundesliga champions could not cope with Liverpool's intensity.

Diaz was the star of the show with a hat-trick, but Liverpool's defenders and keeper Caoimhin Kelleher were always alert to snuff out any rare moments of danger.

Slot took the acclaim of Liverpool's fans at the end, his quiet, understated celebrations a sharp contrast to the fist-pumping antics of predecessor Klopp, after another demonstration of how he is making what many believed was an impossible task look eminently possible.

Bayer Leverkusen subside under Liverpool pressure

Bayer Leverkusen coach Alonso would have been delighted at half-time, with the scoreline blank and Anfield very subdued for a Champions League occasion.

Alonso, who knows from personal experience how the involvement of the crowd can be of such significance at Anfield, made his approach clear as he constantly urged his team to take the heat of the occasion with countless "calm down" gestures to his players.

At every break in play, or when Leverkusen had comfortable possession, Alonso and members of his backroom team were gesturing with their palms down, calling for composure.

It worked to perfection in the first 45 minutes as Liverpool barely laid a glove on Alonso's side and the mood inside Anfield reflected the dull nature of the play.

Diaz's opening goal changed the mood and the emphasis, paving the way for a chastening night for the former Liverpool hero.

Watch highlights of every Champions League game from 22:00 on Wednesday on BBC iPlayer and the BBC Sport website and app.

There will also be a Champions League Match of the Day on BBC One on Wednesday, from 22:40 to 00:00.