2 For 1 At Old Trafford
The trouble started on April 2, 1921.
Stockport County were on their way out of the second division. They were last in the division and had no prospects for the future:
Stockport County hosted Sheffield Wednesday that day, and managed to lose 1-0:
What the figures don’t tell you, however, is the story behind the match. I had to look a few days ahead to find a description:
Unfortunately, I haven’t been able to find any other contemporary reports of the match. However, the long term impacts were pretty severe. The Football Association decided to perform an inquiry, which it did pretty frequently back in those days, and ruled that all matches at Edgeley Park would be suspended until September 12:
Now, if you’re an ignorant foreigner like me and are unfamiliar with the geography of England, you probably don’t know that Stockport is relatively close to Manchester — only about 8 miles southeast of the city, and considered part of Greater Manchester.
As a result, it probably didn’t cause a lot of people to bat their eyes when Stockport’s final Division 2 match in 1921 was moved to Old Trafford. In fact, the game was scheduled for an unusually late 6:30 PM kickoff on Saturday evening, scheduled for after the conclusion of the Derby County - Manchester United match:

The late kickoff, of course, came because Manchester United’s final home game started at 3 PM, the traditional starting time.

In the end, only about 8,000 people were present in cavernous Old Trafford to see lackluster Manchester United finish off its season:
Stockport County, meanwhile, sealed their fate by drawing 0-0 with Leicester City:
Though the official paid attendance was famously only 13 — a fact repeated in every history of Old Trafford — the truth is that a number of United fans stayed on to watch the second game for free. Some sources say there were about a thousand:
Others say 2,000, which is the figure you’re more likely to see in articles about this game:
Either way, that’s the inside story of a rare multi-team doubleheader at Old Trafford — a match famous for only attracting 13 paid customers.