Jurgen Klopp lightly slapped his cheek before placing his palm over his mouth to indicate the extent of his disbelief at the football he had just witnessed.
The Liverpool manager turned towards the technical area, repeating the words ‘oh my god!’ to his assistants, who were still executing frenzied fist pumps.
Sadio Mane, meanwhile, was a picture of conviction. Having sped at, toyed with, then chopped between Nacho Monreal and Calum Chambers to find the top corner for his side’s fourth against Arsenal - and his first as a Red on debut at the Emirates - the Senegal international nodded knowingly.
Others may have been surprised at his mixture of trickery, technique and dynamism, but there was no shock on his part. That is what he could do and intended to continue doing: being direct, decisive, the difference.
Sadio Mane's super speed plus expert finishing and trickery gets referenced quite often, but less noted is his decision-making - so, so good— Melissa Reddy (@MelissaReddy_) March 6, 2017
The 4-3 victory over Arsene Wenger’s side and the ushering in of a new superstar occurred 378 days ago, with the influence and effectiveness of the 25-year-old only rising since.
The question of whether he is Liverpool’s most important player is not the right one, it should be asked if he is now amongst the premier talents in the league. And Mane will undoubtedly keep providing evidence to answer that in the affirmative.
It is his swiftness that is emphasised, but the winger’s decision-making is his most significant quality - an element Klopp has been intent on highlighting.
After Mane’s winner against Crystal Palace last weekend, the German said: “Everyone thinks about how quick he is with his legs and that’s true but he’s quick in mind, that’s maybe the more impressive skill.”
This was further exhibited against Hoffenheim on Wednesday night as Liverpool secured their passage to the group stages of the Champions League with a 4-2 win at Anfield - 6-3 on aggregate. The speedster was a source of constant torment for the Bundesliga side, who struggled to contain or calculate his threats.
He was instructive for Emre Can’s opener, when having hypnotised Havard Nordtveit and Pavel Kaderabek, he waited for the midfielder’s supporting dart around the outside and reverse flicked to him.
Mane then measured matters superbly again for the third goal. After collecting a phenomenal pass from Gini Wijnaldum, he occupied Benjamin Hubner and Nordtveit in the knowledge that Roberto Firmino was breaking ground to provide an option to his left.
He kept possession before backheeling wide for the Brazil international, who lofted a pass across goal for that Can sidefooted at the far post.
Hoffenheim manager Julian Nagelsmann admitted afterwards that no tactical plan could thwart Mane, whose pace alone was enough of a problem without his cerebral play. “I can't put an engine and a propeller on my players,” he said when asked what he could have done to deal with the attacker better.
“That would be illegal on the pitch!”
On Sunday, Wenger will have the same conundrum to solve. Ahead of last season’s meeting at Anfield, the Arsenal boss noted his side would need to put in some shift to stop “the influence of Mane".
Just nine minutes into the encounter, the Gunners had failed in that task, with the forward allowed to cross for Firmino to put Liverpool a goal to the good.
Before half-time, the Brazilian repaid the favour to feed Mane, who took a touch and smashed the ball hard and low past Petr Cech.
The Reds did the double over Arsenal last time out, with the £30 million signing from Southampton central to their victories.
He will look to be the game-changer again at Anfield, having particularly enjoyed this fixture: Mane has hand a hand in five goals in his five previous league starts against the Gunners.
Should the Senegalese turn in another distinguished performance, he’ll further the discussion about his standing in the top flight.
If he has it his way, soon there will be no need for debate and Mane being one of the foremost players in England will be accepted as fact.