The 27-year-old Arthur boxed with intelligence, maturity and ultimately considerable ferocity, flooring Sinitsin in the final few seconds before taking an overwhelming unanimous points decision over 12 rounds. Two judges gave the Russian only one round and another two in respective assessment of 119-108 and 118-109.
In what was a fight game of two halves Arthur survived cuts around both eyes, first from a left hook in the third and then from a head clash in the sixth before piling up a procession of points with an impressive mix of punches. By the time Boris was sent spinning down from a left in the last round he had begun to look the weariest of warriors.
Arthur has reconstructed his career after Michael Gomez brought a temporary halt to his ambitions two years ago. In its way this victory was as impressive a conquest as that of Ricky Hatton over another Russian-born veteran champion Kostya Tszyu. "It's very rare to see this guy on the floor," he smiled afterwards. "I knew he would come here and put up a hell of a battle." For a time Sinitsin did just that. One of the first pro fighters to come out of the old Iron Curtain, he is no stranger to boxing in other folk's backyards; all of his dozen European title fights have been outside his native Russia. He is not a fighter who is easily fazed but Arthur was right in hoping that, not having seen action for nine months, he would fade late.
The contest lacked the hype which surrounded Amir Khan's pro debut in Bolton a week ago, and much of the drama. No bomb scares, just a few explosive punches from Arthur in the later rounds.
It was also relegated to the comparative backwater of ITV2, though still at peak time. Frank Warren's next show, in Cardiff on 10 September featuring Calzaghe and Amir, will be back as a mainstream attraction with the BBC's John Rawling thankfully installed in the channel's commentary seat. Last night another Beeb regular, Jim Neilly, heard all too frequently trying to explain the inadequacies of Audley Harrison's opponents, filled in with Jim Rosenthal back on Formula One duty.
"Amazing" Arthur, as they like to bill him, is bright and articulate, the sort of perky personality upon whom, alongside Amir, Hatton and Joe Calzaghe, ITV can rebuild their old boxing empire.