Arthur, 24, who pipped Jahmene Douglas, 21, to the post in last night's live final results show, winked and gave waiting paparazzi the thumbs-up as he partied with fellow finalists, including Kye Sones and Union J, at the Radisson hotel.
Other stars at the after-party included Chelsee Healey, Xtra Factor host Caroline Flack, TOWIE's James Argent, Little Mix's Leigh-Anne Pinnock and Jesy Nelson and Arthur's proud mother Shirley.
Appearing on Daybreak this morning, the singer-songwriter said: "I'm just going to work hard and get my album out as quickly as possible and not wait around.
"I've got a lot of material to go, so now as soon as I get back into the studio I'll be ready."
Arthur's winning single 'Impossible' is already number one on the iTunes chart, and he added on the breakfast show: "It is starting to sink in, I was overwhelmed.
"That is why my reaction was so still. I couldn't believe it. I actually thought [Dermot O'Leary] said 'Jahmene'."