Arthur (right) is aiming for a world title shot this year

It looked an even fight before Gulyakevich had two points deducted in round six for a deliberate headbutt.

All hell then broke loose, an accidental headbutt by Arthur opening a big cut over the Belarussian's eye.

The fight was stopped in the seventh round and the judges awarded it to Arthur 69-63 68-63 69-64.

It was Arthur's second defence of the belt he won by beating Boris Sinitsin last July. He won another stormy encounter against fellow Scot Ricky Burns in February.

Arthur, who is angling for a world title shot, improves to 23 wins and one defeat while Gulyakevich drops to 18-1.

"I'm obviously happy with the victory," said Arthur. "He butted me quite intentionally and from thereon in I was actually seeing stars a bit.

The only ones who would know if he couldn't make the weight are Alex himself and his trainer, and then I would find out Promoter Frank Warren

"My equilibrium went afterwards but fortunately I got myself together and came back from it. I knew it was going to be tough but I've proved I've got a fantastic chin."

The gangly Gulyakevich caused Arthur, 27, all sorts of problems in the first three rounds, his left hook to the body particularly potent.

But Arthur started letting some good right hands go from the fourth round on and was finding his range with the jab.

Gulyakevich started to unravel in the sixth and launched a spiteful headbutt on Arthur's chin that had the hometown fighter reeling.

Clearly upset, Arthur launched himself at Gulyakevich, landing with a big right hand and following up with a headbutt which opened up a huge gash over his opponent's left eye.

The referee called the doctor up to the ring apron in the seventh round and he decided the fight could not go on.

Under European Boxing Union rules, the fight went to the judges' scorecards and Arthur was ruled the winner after the first six rounds.

After the fight, promoter Frank Warren refuted Scottish legend Ken Buchanan's claim that Arthur should move up a weight division.

Former lightweight world champion Buchanan claimed Arthur was now struggling to make the 130lb super featherweight limit.

Warren said: "What is all this nonsense about the weight? When Ken was fighting there was a stone difference between every weight.

"But things have changed, nutrition has changed and the way people train has changed.

"Alex makes the weight OK. The only ones who would know if he couldn't make the weight are Alex himself and his trainer and then I would find out."

Arthur also rejected Buchanan's suggestion, saying: "Ken is my hero, but he was eating one meal a day when he was making the weight - and he says it is more difficult for me to make the weight than him!"