A game that will live long in the memory of Gunners fans as Arsene Wenger’s side turned out one of the finest European away performances you will ever see.
The Londoners had been humbled 3-0 in the reverse fixture so went to Italy determined to set the record straight.
Their talisman was once again Thierry Henry, though he was joined by a supporting cast of world-class stars who would eventually win the Premier League in fine style.
They took the lead midway through the first half when Henry exchanged passes with Ashley Cole before calmly side footing beyond Toldo in the Inter goal.
The Serie A outfit equalised eight minutes later though there was a touch of fortune about it. Christian Vieri tried a hopeful looking shot that took a wicked deflection off Sol Campbell before looping beyond Lehmann and in off the bar. Anyone who had placed a Champions League bet on the away side would have been gutted.
It was with a slight sense of injustice then that Arsenal went into the break level, but they would take no prisoners in the second half.
Just four minutes into the second period and Arsenal were ahead again. Henry was the provider this time, swinging the ball in from the left and finding Swede Freddie Ljungberg who tapped home from close range.
The goal brought Inter back to life and they started to mount a fight back but the Gunners defence, marshalled by the excellent Lehmann and Campbell, held firm. As the Italians pushed forward space began to open up at the back, allowing Arsenal to pick them off at will.
With nine minutes left Henry finished the tie on the break when he raced away from Javier Zanetti and planted the ball beyond Toldo.
Six minutes later it was four, when Brazilian Edu tapped home from close range with Inter committing too many men forward.
The hammering was confirmed in injury time when Frenchman Robert Pires was given time and space to fire home. It put the seal on something of a Champions League betting upset.
It was a result that sent shockwaves through Europe and confirmed Arsenal as a genuine force once more, though they would eventually drop out of the competition in the knock out stages.
It would be another three years before Arsenal finally reached a Champions League final against Barcelona in 2006, but they would finish the 2003/04 domestic season unbeaten with a side now known as the invincibles.