Taylor was defending his four belts against mandatory challenger Catterall as the Scot retuned to Glasgow for the first time in three years
Jack Catterall was robbed of victory by the judges as Josh Taylor controversially clung on to his four world titles.
The Scot, a shadow of his imperious best, was dropped in the eighth round as Catterall looked set to cause a huge upset.
Taylor desperately needed a stoppage in the final rounds but failed to rally as both men were deducted points for fouling.
But instead of a new champion being anointed by the judges, two of the three gifted victory to the Scot.
Taylor was fighting at home for the first time since he was crowned world champion almost three years ago.
He returned to Glasgow as Scotland’s first four-belt champion having completed his collection by beating Jose Ramirez last year.
Catterall had stepped aside to allow Taylor to face Ramirez but was now cashing in his mandatory challenger chip.
An edgy first round was punctuated by Catterall’s left hand as the visitor made an assured start.
Taylor returned the favour in the second but his challenger was more than up to answering back.
The champion continued to neglect his jab into the third session as Catterall belied his pre-fight odds.
Both men were repeatedly warned for fouling as Taylor tried to turn the bout into a dog-fight.
And the Scot appeared to signal his distress to his corner in the fourth session.
The 12,000-strong crowd tried to rally their man in the fifth round as they sensed he was in trouble.
Taylor was cut below his right eye as this tougher-than-expected test reached the halfway stage with the champion trailing.
Taylor continued to attempt to drag the Englishman into the trenches but it was Catterall who was landing the crisper shots.
And he dumped Taylor on the canvas in the eighth round with a left hook to the head.
The champion attempted to rally in the next session but he was staring down the barrel of an upset.
He was given a glimmer of hope when Catterall was docked a point for repeated holding in the 10th.
But Taylor still – apparently – needed a stoppage in the championship rounds but instead, as the blood streamed down his face, he hit Catterall after the bell for the end of the 11th and had a point deducted.
With his fate seemingly all but sealed, Taylor desperately chased a final-round stoppage but was left clawing at thin air before the judges saved him.
On the undercard, Nick Campbell was crowned the first Scottish heavyweight champion for 71 years after stopping Jay McFarlane.
McFarlane, who was content to lead with his face throughout, was dropped in the seventh round.
He beat the count but the referee stepped in after another barrage from the undefeated Campbell.