Expect Southampton to get a letter from the FA over this action from one of their fans in the 2-0 win over Arsenal this afternoon
SkySports has the details of the arrest/storming:
The suspect, from Lymington, Hampshire, was still being questioned on Thursday night by Hampshire Constabulary officers.
A Hampshire Police spokesman said: "Police have arrested a 25-year-old man from Lymington following an incident on the pitch at St Mary's at the end of the Southampton versus Arsenal match.
"The man was arrested on suspicion of going in to an area adjacent to the playing area contrary to the Football (Offences) Act 1991.
"The man remains in police custody. Officers are investigating the circumstances to establish whether any criminal offences have been committed."
Here's Wenger after the match discussing the fan
((HT: Daily Mail))