Police are appealing for witnesses following an assault in Chatsworth Road, Worthing, on Friday morning (Friday, July 19).
It was reported that a man approached two women in the car park at the Guildbourne Centre, and pushed one of them, causing a cut to her head.
Two men, friends of the women, went to their aide.
A 29-year-old suffered a stab wound to his back, for which he has been treated, and released from Worthing hospital. The other man, aged 26, suffered a cut to his hand.
The incident happened at about 2.30am.
DC Laura Sinden said: “This was a nasty attack which escalated with the use of a knife. I would ask anyone who witnessed the assault to come forward. “Anyone with information is asked to contact police on 101 quoting serial 125 19/7 or the independent charity Crimestoppers on 0800 555 111.”
A 22-year old man is in custody helping police with their enquiries.