Seven-time winners AC Milan, playing in their first Champions League match in seven years, were given a rude 3-2 awakening at Anfield.
Jordan Henderson's stunning strike ensured Liverpool came from behind to beat AC Milan once more with a pulsating 3-2 victory at Anfield to get their Champions League campaign off to a winning start.
The Reds famously came from 3-0 down to beat the Italian giants on penalties in the 2005 Champions League final in Istanbul, but should have made far easier work of disposing of Stefano Pioli's men on their return to top level European football.
Seven-time winners, Milan were playing their first Champions League match for seven years and were given a rude awakening to step up in class but for a two-minute spell before half-time that threatened to take the game away from Liverpool.
What a goal from Liverpool captain, Jordan Henderson 🏴 pic.twitter.com/H3TktxFuqz— Wyngback Football ⚽️ (@wyngback) September 15, 2021
Fikayo Tomori's early only goal was scant reward for the home side's early dominance as Mike Maignan saved Mohamed Salah's penalty.
But goals from Ante Rebic and Brahim Diaz turned the game on its head completely against the run of play.
Salah levelled the scores once more before Henderson's thunderous finish proved a deserving winner 21 minutes from time.
Jurgen Klopp took a risk with his team selection as he rested Virgil van Dijk, while Divock Origi was handed his first start of the season up front at the expense of Sadio Mane.
The changes did not disrupt the Reds' rhythm in a blistering start, but the lack of a prolific centre-forward in Klopp's squad was again exposed.
Origi sliced wide a great chance from Andy Robertson's cross before Diogo Jota saw a shot deflected just wide and Maignan made the first of a string of big saves from Joel Matip's header.
Liverpool's pressure eventually paid off when Trent Alexander-Arnold burst into the box from right-back and his shot was turned into his own net by Tomori.
Salah could not keep his long scoring streak from the penalty spot going on 14 minutes after Robertson's shot was handled inside the area by Ismael Bennacer.
The Egyptian had scored 17 consecutive penalties for Liverpool dating back to 2017, but Maignan parried his powerful effort and Henderson's follow-up on the rebound.
The visitors appeared to be missing the presence offered by the injured Zlatan Ibrahimovic up front.
However, Anfield was stunned as the Milan attack suddenly clicked just before the break.
Rebic slotted home Rafael Leao's through ball to level.
The Croatian then turned provider two minutes later for Alexis Saelemaekers and when his effort was blocked on the line by Robertson, Diaz followed in to tap into an unguarded net.
Liverpool's three goals in Istanbul 16 years ago came in six minutes and Milan nearly exacted revenge with the same feat either side of the break only for Simon Kjaer's strike to be ruled out for offside.
A pulsating game had another momentum swing moments later when Origi's lofted pass played in Salah to prod home from close range.
Roared on by the first Anfield crowd for a European night since March 2019, Liverpool found their second wind and a winner.
A corner was only partially cleared to Henderson on the edge of the box and the England midfielder smashed the ball first time low past Maignan.