Liverpool built a Champions League reputation on their 2005 second-half recovery against AC Milan and they were required to come from behind again to get their European campaign off to a winning start.
The achievement was considerably easier than the seemingly gargantuan task of recovering from 3-0 down against the then mighty Serie A giants but they made much harder work of their 3-2 victory at Anfield than they should have done.
Such was their early dominance Jurgen Klopp's side should have been out of sight well before Ante Rebic and Brahim Diaz scored within two minutes of each other just before the break to surprisingly turn the match on its head.
Trent Alexander-Arnold's ninth-minute shot had deflected in off Fikayo Tomori before Mohamed Salah missed the chance to establish an early platform with his first failure from the penalty spot in 18 attempts.
Despite trailing at half-time, Klopp would not have had to produce the rallying speech Rafael Benitez did in Istanbul as there had been very little wrong up to the point where they lost all defensive shape moments before the interval.
And even though Milan finished a distant second to city rivals Inter last season, they are not blessed with the star power of a Kaka, Paolo Maldini or Hernan Crespo and without the injured Zlatan Ibrahimovic, they lack real quality.
Liverpool turned up the heat with Salah's 72nd goal in his 100th appearance at Anfield, shortly after the restart provided the necessary momentum and Jordan Henderson secured the win with a low half-volley.
Milan may have won seven European Cups but this was their first outing in this competition since 2014 and their inexperience showed as they constantly gave away possession having found themselves under pressure from the moment they won the toss and invited their hosts to attack the Kop.
Divock Origi, a surprise starter for the rested Sadio Mane, missed a good early chance, Diogo Jota had a shot blocked and Joel Matip's header – destined for the top corner – was caught by goalkeeper Mike Maignan.
However, the strain told as Alexander-Arnold exchanged passes with Salah and charged into the area where his angled shot bounced up off Tomori and into the net.
It did nothing to help Milan's nerves; the waves of attacks just kept coming and when Andy Robertson's cross hit the arm of Ismael Bennacer, Salah had the chance to double their advantage but Maignan saved his penalty and Jota's follow-up.
The miss appeared to stall the hosts' momentum – their best chance after that saw Salah's snap-shot tipped over – and that gave Milan some encouragement but, after the previous 42 minutes they had endure, even they could not have foreseen their finish to the half.
A neat passing move on the edge of the penalty area exploited the channel between centre-back Matip and Alexander-Arnold and Rebic rolled a shot past Alisson.
Their second came from a similar position, with Alexander-Arnold caught upfield, and although Robertson blocked Theo Hernandez's shot on the line, Diaz followed in to score.
It was uncharacteristically loose from Liverpool but the absence of the calming influence of the rested Virgil Van Dijk offered some explanation.
So another comeback against the Serie A giants was required but, judging by the evidence of the first half, it was entirely achievable.
Salah's 27th Champions League goal in 46 matches, three minutes after the break after exchanging passes with Origi and poking home the dropping through-ball was the ideal start.
But they had to wait until the 69th minute to get back in front when Henderson drilled in a low half-volley from the edge of the penalty area after a half-cleared corner.
At the final whistle there were no celebrations from the players and it was left to Klopp to produce his now-trademark triple-fist pump in front of the Kop to signify the return of European football to a full house at Anfield.
