Law enforcement sources tell TMZ out of the massive crowd at the Old Trafford cricket ground, police made just the one arrest. We're told the bloke was busted for drunk and disorderly conduct.

The sole perp was arrested in the middle of audience after he started to get disruptive. Cops hauled him away before anything got out of hand. The fact it didn't -- in such a large crowd -- shows the mood in Manchester was all about compassion.

In this case ... one bad apple did NOT spoil the whole bunch.