Arsène Wenger was involved in a brief flashpoint with a pitch-invading fan at St Mary’s Stadium, where Arsenal began the new year with a 2-0 Premier League loss to Southampton.

The fan ran in front of Wenger and the Arsenal bench during the second half and he appeared to gesture towards the manager. The supporter was later arrested. He was not wearing any colours, so it was unclear whether he was a disgruntled Arsenal fan or a goading Southampton one.

Southampton believe he was an Arsenal supporter who had run on from a part of the home enclosure while Wenger thought he was a Southampton fan. He was led away by security and Wenger later shrugged off the incident. “It was a young boy,” Wenger said. “I think he was a Southampton fan. He was not aggressive at all. I don’t think he said anything. Honestly, he was not aggressive.”

The incident follows the foul-mouthed abuse Wenger received when he boarded a train from Stoke following Arsenal’s 3-2 defeat at the Britannia Stadium. Wenger was told then to leave the club but proceeded to steer his side through five consecutive undefeated games in all competitions.

Wenger had greater worries as his goalkeeper, Wojciech Szczesny, and his back line were guilty of basic lapses, which helped to give Southampton both of their goals. He described the loss as “self-inflicted”, adding: “We made the mistakes in our final third that allowed them to win the game. We had lapses of focus in vital areas and we paid for it.”