After a 3-0 loss to Inter at Highbury and a 2-1 defeat in Kyiv, Arsenal were in trouble in Group B.

Failure to beat Inter on matchday four, coupled with an unfavourable result elsewhere, would have knocked them out of the Champions League.

Despite the risk of failure, supporter Mark recalled Luton airport being packed with "Gooners" at a "ridiculously early time".

Some Arsenal fans made the trip to Milan a few days in advance including Guy McIntyre, who spent the night before on an Inter fan's floor.

Arsenal may have been flying in the league with 10 wins from 13, but they were facing an Inter side who had already beaten them and had far better European Cup pedigree.

The then two-time winners had reached the semi-finals of the Champions League the season prior and were only knocked out on away goals by eventual winners and fierce rivals AC Milan.

To the game, which started in misty, drizzly conditions.

Both Richard Ryan and Kelvin told BBC Sport they had accidentally bought the wrong tickets and found themselves in the home end, desperately trying to hide their Arsenal allegiances.

The duo's stealth was called upon in the 25th minute when underdogs Arsenal opened the scoring through Thierry Henry.

The Frenchman silenced a chorus of booing home fans by receiving the ball off Ashley Cole and side-footing home from the edge of the box.

Henry then continued to dance passed Inter's defenders at will, but the hosts responded and were level before the break when Vieri's shot deflected wickedly off Sol Campbell, was tipped on to the bar by keeper Jens Lehmann but bounced in.

Arsenal supporter Dr Dave was in an Irish pub in Venice "stuffed full of Inter fans". He said: "We were 1-0 up and then there was a five-minute power cut - the lights came back on with the score at 1-1 and the place erupted."

With the score 1-1 at half-time, Arsenal were heading out of the Champions League, and yet they produced an inspired second-half performance - one of the club's best ever in Europe.

"I remember the first half was pretty even but in the second half, shooting down towards our corner, Henry, [Robert] Pires, Edu and co. ran riot, sending us ecstatic!" added Guy Wisemen, who was also at the game.

Arsenal retook the lead within five minutes of the restart when Henry cut inside and found Freddie Ljungberg, who fired into the bottom corner.

It was then a case of Gunners dominance as they looked for a third and a two-goal cushion, and it eventually came in the 85th minute through an Henry stunner.

The Frenchman collected the ball from inside his own half, charged into the box, beat Javier Zanetti with a trick, and then smashed one into the bottom corner.

In the Inter section Richard had already been kicked out for celebrating Ljungberg's goal, while Kelvin "went bonkers" for Henry's strike but managed to stick around by "speaking a little Italian".

Three minutes later and Arsenal grabbed another as Henry's cross missed Ljungberg in the middle but fell kindly for Edu, who passed into an open goal.

Chaos, confusion and delirium for Arsenal supporters.

One minute later and the thrashing was complete when Jeremie Aliadiere, on as a late substitute, slipped the ball to Robert Pires for number five.

Arsenal's then biggest ever win in the Champions League put them second in Group B, one point behind Lokomotiv Moscow who they beat 2-0 two weeks later to go through as group winners.

Wenger said the Inter result was "beyond his wildest dreams" while Ashley Cole said it was like England's 5-1 win over Germany "but even better".

"Henry was unplayable that night and it's probably my favourite away match ever," added Guy McIntyre.

"Twenty-four hours in Milan, I will never forget it."

Arsenal ended up being knocked out at the quarter-final stage by Chelsea, but in the league that season they were unbeatable.

After the Inter match they won 16 of their final 27 Premier League games, lifting the title, and with it the Invincibles were born.