A double rapist violently attacked another woman while he was on early release from prison.
Fraser Summers, 30, was jailed for nine years in 2010 for targeting two prostitutes in separate incidents.
But after being released Glasgow Sheriff Court heard he attacked Lauren Cusick and her friend last April.
Summers was found guilty of behaving in a threatening or abusive manner, two assault charges and resisting arrest.
The trial heard he grabbed Ms Cusick on Sauchiehall Street, Glasgow after he left The Savoy nightclub.
He throttled her against a shop window before chasing Glen Faulkner.
Summers then resisted arrest by refusing to allow officers to handcuff him.
The sex offender, from Robroyston, Glasgow, denied assaulting anybody and claimed he was the victim of threats.
But Sheriff Eric Brown rejected his version of events and branded him "wholly incredible".
The court heard from Ms Cusick and her friends who described Summers making an "obscene gesture" and acting aggressively.
Ms Cusick told how she was "terrified" when Summers grabbed her and held her by the neck against the window of an EE phone shop, near McDonald's.
Summers squeezed her neck and punched her face.
Ms Cusick went to hospital and was given painkillers but had to take time off work after the attack.
Mr Faulkner described being "taken aback" by Summers, who turned on him.
Summers chased him up the street, throwing his arms and trying to hit him but only made contact with his shoulder.
Another member of the group, Jasmine Williamson, told a nearby police officer what happened and pointed Summers out.
But he refused to allow the officers to put handcuffs on him and lay on the ground as a dead weight.
They called for assistance and several officers arrived and helped to get Summers in the back of a police van.
He was recalled to custody to serve the remaining part of his High Court sentence.
Sentence was deferred on the current case until next month for reports.
During his rape trial Summers had accepted that he had attacked the women, but claimed that any sexual activity was consensual.
The court heard that he attacked his first victim in November 2007 at ground in the Broomielaw area of Glasgow.
Summers struck again in April 2008 on waste ground at Carrick Street when he raped a second woman.
He was also convicted of punching two women at the Tunnel nightclub in Glasgow in November 2008.