Jack Wilshere smiled. Everyone connected to Arsenal smiled because there was simply so much for them to smile about. Tottenham Hotspur had been dismantled. Wilshere was prominent among the headline acts (again) and the momentum around Arsenal seemed irresistible.
And the cherry on top? From an Arsenal point of view, give or take the knee injury, it was the sight of Theo Walcott smiling cheekily at the away supporters as he was chaired off on a stretcher and depicting the two-nil scoreline with his hands.
That brought another wave of coins and assorted missiles down on him and the unfortunate stretcher-bearers, who must surely have been tempted to abandon protocol and make a short-cut across the pitch to safety.
Walcott, and the stretcher-bearers, might reflect that it was not the smartest thing he has ever done, given that the Tottenham fans were already wound tightly, although the forward did have the presence of mind to denote the Arsenal goal tally with the reverse V-sign.
The gesture was not offensive and so the Football Association is unlikely to bring any charge of crowd incitement against Walcott. It is the Tottenham coin-throwers who will face investigation.
Once out of harm's way and down the home straight of the main stand Walcott, by now wearing a red-and-white Arsenal scarf that had been lobbed to him, resembled the conquering monarch. He did not look to be feeling any pain from the knee injury, which could keep him out for four weeks. There was the overriding impression of schoolboy hilarity.
"He'll be an Arsenal legend now," Wilshere said, smiling. "They love Theo already and this is only going to help him. They [the Tottenham support] were giving it to him and he's given a little bit back. I think people have got to look at it as banter. He's a bit smarter than me, I suppose."
Another smile. When Wilshere was abused by a section of the Manchester City crowd at the Etihad Stadium three weeks previously, during Arsenal's 6-3 Premier League defeat, he responded with a single-finger salute. A scoreline gesture was not an option for him. He was banned by the FA for two matches – the derbies against Chelsea and West Ham United.
But Wilshere has returned in style. He was very good in Arsenal's 1-0 win at Newcastle United; he was the man of the match in the 2-0 home win over Cardiff City; and he excelled, alongside many others, against Tottenham.
There was a spikiness about Wilshere in Saturday's FA Cup tie. He had a running battle with Mousa Dembélé and he appeared to be on the edge, at times, emotionally – which, of course, fans love to see in derbies. "As an Arsenal fan myself," Wilshere said. "I really enjoy these wins. I've got Spurs in my family and a bit of West Ham so pride is at stake in a derby and we did well. If you win the battle, you win the game. We did that."
More encouraging was Wilshere's offensive drive and the explosiveness of his acceleration. There were form and fitness concerns about him at the beginning of the season in light of his well-documented foot problems but Arsène Wenger has learnt lessons and handled him with care. He withdrew him on 71 minutes against Tottenham.
The manager has been helped by his greater options in midfield, following the summer signings of Mesut Özil and Mathieu Flamini. When he has rotated, there has been no shortfall in quality. Wilshere has played in central positions of late and three top performances in seven days have given rise to optimism.
"I wasn't injured when I came off," Wilshere said. "I was just tired after the three games. We've got quite a good squad now and that will help us. Over the last few years, we've struggled with that but this time we've got a good squad and we've been able to rotate in midfield."
Tottenham's midfield, or the manner in which it was outnumbered and overrun up until the excellent Tomas Rosicky punished Danny Rose's error to make it 2-0, following Santi Cazorla's first after half an hour, was a talking point.
Tim Sherwood immediately substituted the striker Roberto Soldado, switched to 4-2-3-1 and watched his team finish on the front foot, although they did not create any chances. Sherwood's 4-4-2 has served him well in his four Premier League matches but it seemed a dirty word at the Emirates.
"I didn't see us playing 4-4-2," Sherwood said. "We just had 11 numbers on the field.
"We tried to rotate and fill up every area. [Emmanuel] Adebayor dropped deep and picked up the ball and our wide players funnelled in. I don't think we were ever two players in midfield."
Sherwood revealed that Soldado had soreness in his calf – he almost did not make the game – and the club's injury list is onerous, comprising Jan Vertonghen, Younès Kaboul, Kyle Naughton, Sandro, Paulinho, Andros Townsend, Lewis Holtby, Gylfi Sigurdsson, Erik Lamela and Jermain Defoe. It is to Sherwood's credit that he has not moaned about it.
He enjoyed an encouraging performance from the 19-year-old midfielder Nabil Bentaleb but it was the 18-year-old Arsenal winger Serge Gnabry who merited top billing. Gnabry was brave, quick and incisive. "He's like a little boxer, a little fighter," Mikel Arteta, the Arsenal midfielder, said. Tottenham saw stars.
Man of the match Serge Gnabry (Arsenal)