After a spell of one defeat in 11 to take the lads to the top of FA Premier Reserve League South, coach Clive experienced the other side of the coin at Stevenage Borough as the Saints racked up a 5-0 win.
It was a strong Saints side - Jason Dodd, Matt Oakley, Chris Baird, Jo Tessem and Dexter Blackstock all played - but the result and performance was a shock to the system.
Clive summed it up in simple terms. "Southampton were very experienced and put in a good performance whereas we were poor," he reflected.
"There is no doubt that it was our worst performance of the season but as a coach, I will take a lot out of the game in terms of what I'll learn about individuals and the team collectively.
"They know how disappointed I am, they feel disappointed themselves and I'll be honest, that's not the team I've seen all season."
Could he put his finger on what went wrong? "Individual errors and things I didn't think I'd say about the group, a commitment to do what I call the 'ugly' things that they've done all season.
"Southampton's experienced players did it the right way and made challenges, wanted to run off the ball, passed it well and had a spirit that we've had all season but didn't have on the night.
"I know what we are capable of and that's the most frustrating thing - the lads have not produced it.
"It's a bit of a shock to the system but we now have to show the determination to turn it around."
Clive Allen believes he'll learn a lot more about his reserve group after the heavy defeat by Southampton last night.