West Ham and Millwall hadn't faced each other for four-and-a-half years when the two teams were drawn together in the League Cup back in 2009.
The Hammers had been promoted to the top flight some years prior while Millwall were languishing two divisions below in League One.
In their past six meetings, West Ham were winless against their great rivals and had not tasted victory over the South Londoners for the past 18 years, adding further fuel to the fixture.
Ex-West Ham defender recalls pitch invasion derby win over Millwall
Former Manchester United defender and United States international Jon Spector, speaking to FourFourTwo via a top live odds site, recalls the build-up to the match, in which Millwall's visiting allocation was limited to 1,500 instead of the usual 3,000.
"It was surreal," Spector says. "I remember we didn't normally meet up as a team at a hotel for a home game. And so we did that, and we ended up then taking a bus to the stadium, because they knew that there could be some issues getting [there], they didn't want the players driving their cars there and running into any problems."
The Hammers had begun the season with a win over Wolverhampton Wanderers but were beaten in their next match versus London rivals Tottenham Hotspur at Upton Park.
"We took the bus, and everything around the stadium was boarded up, the windows, it was as if they knew, we're expecting trouble. Honestly, it was very strange, and it was as if, like in my time in Florida, you're preparing for a hurricane to come through, and you board up the windows and all that."
Those anticipating potential trouble must have been cursing Millwall striker Neil Harris when he struck during the first half to give the third tier side a surprise lead.
Hammers man Jack Collison struck the upright, while Millwall fans clashed with police in what was a fraught encounter from start to finish. Mark Laird almost doubled the visitors' advantage with a long-range effort during the second half, hitting the stanchion behind the goal instead of the back of the net.
Trouble continued in the stands as swathes of Upton Park stewards and police did their best to keep West Ham supporters at bay, as they made repeated attempts to reach the Millwall section.
Spector recalls an 'electric' atmosphere on account of what happened next.
Just as the Hammers appeared to be heading out of the competition, teenager Junior Stanislas connected with Frank Nouble's cross to level the game with three minutes left of normal time.
"There were multiple pitch invasions and so it was a very interesting time.
"So the pitch invasions were all from, if I remember correctly, West Ham fans, so I wasn't really kind of concerned, and it was one or two people here or there, that was it. So it wasn't like a whole mob of people." Spector added.
After a brief delay in clearing the pitch of spectators, the match went to extra-time. Following the restart, West Ham were awarded a penalty for handball inside the area, which Stanislas tucked away for his second of the night. Once again, fans invaded the pitch.
"Interestingly enough, that was the first game my wife - we were not married at the time - but first game she had ever attended in England", Spector adds. "I remember after the game, her saying, 'Are all the games like this?' And I said, no, not at all, not at all! So she certainly remembers that game as well."
Zavon Hines added a third late on to secure West Ham's passage to the next round but with emotions already heightened, disorder spilled out onto the adjoining streets around Upton Park at full-time.
One Millwall supporter was stabbed, and the Football Association subsequently condemned the scenes, issuing West Ham with a �115,000 fine. Ex-Hammers boss Harry Redknapp urged football's authorities to prevent the two clubs from ever playing each other in a cup match again.
Eighty arrests were made, while West Ham banned 54 supporters for life. The two teams have played each other since, although the last time they met was in 2012.
Spector went on to play for Birmingham City, Orlando City and Hibernian before retiring in 2019. He won 39 caps for the United States.
