Ashton, 25, was out celebrating his anniversary with his girlfriend when he was glassed by a stranger.
He suffered cuts to his face, but did not require stitches.
And the new boy at Saracens was praised by the club’s chief executive Ed Griffiths for not retaliating.
"People will inevitably see this story and say an England rugby player is in trouble again," said Griffiths. "For clarity, Chris Ashton is not in trouble at all.
"Since arriving at the club, Chris has proved himself an outstanding member of the Saracens family, on and off the field.
"It is a reality that well known sports people are provoked by strangers and subsequent events are instantly tweeted."
England coach Stuart Lancaster spoke to Ashton after the events, and was satisfied that his player was blameless in the incident.
"England have looked into the incident and consider the matter closed," said the Rugby Football Union in a statement.
Ashton himself took to Twitter to play down the events, saying simply: "So, some bloke decided to spoil an evening out for me and my misses [sic]. No stitches needed – back to work tomorrow."