Arsenal were clinging to a 2-1 lead, their backs to the wall, as Liverpool stormed at them in tidal waves of attacks. Henry was alone, policed by two Liverpool players in the centre circle.
When the ball came to him he played it wide to the empty space on the left. He chased it, caught Jamie Carragher, beat him to possession, cut inside and picked his spot: Genius. He had passed to himself and ensured an early exit for the FA Cup holders.
Add that to an Arsenal performance that was "united, determined, disciplined," according to manager Arsene Wenger."
Until Henry's magnificent intrusion, a lightweight from Prague, Tomas Rosicky, had looked like being the heroic two-goal Arsenal match-winner but when Dirk Kuyt pulled one back inn front of the Kop, Liverpool went for it.
They pounded the Arsenal defence, attacking the Kop end backed by a crowd that even Wenger admitted "were fabulous, kicking every ball for 90 minutes."
Henry changed all that, killing the game for Liverpool with Liverpool manager Rafa Benitez lamenting: "When you make mistakes against these players you are punished. We will think about solutions for the future. The immediate future is that the teams meet here again on Tuesday in the Carling Cup. But this was the big one.
The atmposhpere burned as the titans titans on the pitch squared up. Between them these heavyweights have won five of the six FA Cup Finals played at the Millennium Stadium, Cardiff, and a date at rebuilt Wembley in May carried the appeal of history as the first team to win and enjoy the new furniture. Forget it, Arsenal.
Both Wenger and Benitez had fixture congestion on their minds and that was reflected in their personnel. Both fielded second choice goalkeepers and Craig Bellamy, who has been involved in some golden Premiership moments with Liverpool was alongside Sami Hyypia on the bench.
Those involved found themselves working in a cauldron of tention. No one was giving way. They moved the ball around quickly. There was bite in every tackle and referee Steve Bennett was busy with his pencil as Liverpool's Luis Garcia (diving) and Arsenal's Philippe and Gael Clichy went into the book for fouls that were not particularly violent with the match barely half an hour old.
Everything was hectic, footballing tit-for-tat mostly in midfield with the occasional shot---Xabi Alonso fired over the top and Manuel Almunia palmed away from Dirk Kuyt---until Arsenal struck.
Ten minutes from half-time they came away down the right. The inter-play between Tomas Rosicky and Alexander Hleb was imaginative and sharp enough to breach Liverpool's defences.
The Arsenal pair exchanged passed before Hleb rolled the ball back into the middle with his left foot for Rosicky to meet it with his right and wheel away, a picture of joy, as the ball flew into Jerzy Dudek's right, top corner.
The Kop fell silent ---their team hadn't conceded a goal at home in the previous eight games --and Arsenal turned on the style, spraying the ball about on the greasy turf, everything about them showing a rise in confidence. Not quite a swagger but cool in the skirmish.
It showed in their second goal seconds from half time. It was a Rosicky solo as he fiddled his way along the edge of the penalty area with the ball tied so tightly close to his boots that the Liverpool defenders were unable to get in a block or a tackle as he shuffled past them before striking the ball low past Dudek.
Good goal. Poor defending and enough, you were entitled to think, that Arsenal's place in the fourth round was assured. With Liverpool attacking their favourite Kop end for the second 45 minutes there was plenty of fight left in the match.
The pressure was on. Liverpool came at them in waves but found Arsenal's defenders organised and resilient although they must have felt a huge sense of relief when goalkeeper Manuel Almunia raced to the edge of his penalty area to thwart Steven Gerrard who had slipped clean through the cordon.
Almunia cleared that with a fly-kick. His handling on other occasions as Liverpool tossed the ball in towards Peter Crouch had been impeccable.
Liverpool were pouring forward deep into the second half with the crowd bawling them on. You felt that Arsenal, for all their discipline, would crack at some point and, sure enough, their goal after 71 minutes ignited the atmosphere
As the clock ticked on Arsenal knew they were in a dire, back-to-the-wall operation to hold on to their slender lead. They needed a break and they received the one that mattered six minutes from the end courtesy of the immaculate Henry.
Benitez blamed defensive mistakes. Wenger purred. Any team that goes away from Anfield with a 3-1 win is entitled to sing all the way home.