Two goals in the space of four minutes granted Birmingham City an unexpected reprieve at St Mary's last night.
Alex McLeish's side were trailing to Southampton side standing 60 league places beneath them and appeared on the verge of an embarrassing exit before Lee Bowyer side-footed home a goal to cancel out a sumptuous curler from Adam Lallana six minutes into the second half.
Lee Carsley scores his team's second goal
Winner: Lee Carsley scores his team's second goal
The equaliser deflated the home side, and Bowyer's midfield partner Lee Carsley capitalised on hesitancy in the Southampton defence to steer a second Birmingham goal under the body of goalkeeper Kelvin Davis.
The result was rough justice on Southampton, who had until then made light of their plight nine points adrift at the foot of League One to lead their Barclays Premier League opponents with a vibrant display.
Five years ago, this was a Premier League fixture, a goalless draw played out in front of 27, 568 spectators at St Mary's. If the latecomers eventually swelled the attendance last night to 11,753 -a level that bordered on the respectable - there were still great swathes of empty red seats to indicate how a combination of life in League One and a Carling Cup second-round tie has sapped enthusiasm by the Solent.
Adam Lallana (C) of Southampton is congratulated by his team mates
Scorer: Adam Lallana (C) of Southampton is congratulated by his team mates
The 631 fans who travelled from Birmingham were more interested in the shortened substitutes bench listed by McLeish, with only five players being named instead of the seven permitted.
Prospective club owner Carson Yeung will no doubt have interpreted that as a pointed message from his manager about the thinness of the squad at his disposal.
But, with the takeover not due until September at the earliest, the hint cannot be the police didn't seem to be able to stop it. There were quite a few people injured. It was nasty.'
Onlookers said Green Street, close to the ground, was filled with several hundred West Ham and Millwall fans before the match.
They said the first bottles and bricks were hurled shortly after 6pm. A 29-year-old man, who runs a kebab shop in Green Street, said: 'All hell broke loose, it was very frightening. It's not every day you see stuff like that.
Chris Peary (L) of Southampton blocks James O'Shea of Birmingham
Battle: Chris Peary (L) of Southampton blocks James O'Shea of Birmingham
'There were West Ham fans on one side and Millwall on the other. They were being kept apart by the police. There were West Ham fans for as far as you could see along the street. 'Bottles and bricks were being thrown from the back and some were hitting West Ham fans at the front. There were loads of people with blooded faces.'
He said he closed his shop for two hours as the violence flared but added that the clashes continued after the match kicked off.
Another man, aged 19 but who did not want to be named, said: 'People were chipping bricks off buildings and throwing them at police. I saw one officer getting kicked as he was on the ground.'
Rubbish, shards of glass and beer cans were strewn across Green Street and bricks could be seen in rubbish bins. About 50 police officers in riot gear had congregated outside Upton Park tube station as they waited for the final whistle. Several hundred fans were seen leaving the match before the game ended. A Metropolitan Police spokesman said: 'It looks like there has been some planned trouble from fans. Hundreds of fans are estimated to be involved.'
The 44-year-old stab victim was said to be in a stable condition. One pub reportedly had its windows broken by bricks during running battles across several streets up to half a mile from the stadium.