The Gunners had the lead on three separate occasions but that still wasn’t enough to see them through as some schoolboy defending kept gifting the Reds a way back into the match, heaping more pressure on the embattled Unai Emery in the process.
In the end, it was local lad Curtis Jones who struck the winning spot kick as Jurgen Klopp’s band of teenagers capped a remarkable fightback.
With both manager’s making 11 changes from the last games, it was Liverpool who settled the quicker and they took the lead after six minutes when Shkodran Mustafi put through his own net from Alex Oxlade-Chamberlain’s cross.
Arsenal responded well to the setback though and levelled when Lucas Torreira tapped home from close range in the 19th minute after Bukayo Saka had been denied smartly by Reds goalkeeper Caoimhín Kelleher. There was a suspicion of offside over the Uruguyan’s goal but with VAR not active in the EFL Cup, the goal stood.
The home side were then caught napping for Arsenal’s second, a quick free kick unleashing Ainsley Maitland-Niles and his cross was eventually fired into the roof of the net by Gabriel Martinelli.
Martinelli grabbed his seventh goal in four starts for the Gunners on 36 minutes when Liverpool again went to sleep at the back, Mesut Ozil releasing Saka after picking the pocket of Joe Gomez. Saka then rolled the ball across the face of goal for Martinelli to side foot home.
With Liverpool on the ropes, they were gifted a lifeline just before half-time when Martinelli was adjudged to have brought down 16-year-old Harvey Elliott inside the box. Up stepped James Milner to change the complexion of Jurgen Klopp’s teamtalk.
It could have easily been 3-3 at the break had Divock Origi failed to head home Elliott’s cross in first-half stoppage time.
The second half brought more of the same, Maitland-Niles tapping in a fourth after a Milner mistake, Ozil keeping the move alive with some magic to set up the visitors for the fourth.
But back came Klopp’s men, Oxlade-Chamberlain unleashing an unstoppable strike from 22 yards to reduce the deficit.
Origi then levelled the match with a powerful strike from the edge of the box that Arsenal goalkeeper Damien Martinez couldn’t keep out.
With the momentum seemingly with Liverpool, Joe Willock scored a contender for goal of the night as he drove from midfield before bending the ball before Kelleher.
Arsenal finally dug in and showed some defensive solidarity but couldn’t hold on for the winner, Neco Williams digging out a cross in stoppage time for Origi to level with a bicycle kick.
In the resulting penalty shootout, only Dani Ceballos missed for Arsenal, Kelleher denying him smartly to set up Jones to score the winning spot kick.