Nathan Richardson, 19, attacked Wenqing Xu on New Year's Day in Preston, Lancashire, after taking a cocktail of drink and drugs at a house party.
Mr Xu, who was found near Plungington Community Centre, had been in "the wrong place at the wrong time", Judge Mark Brown told Preston Crown Court.
Richardson, of no fixed address, must serve a minimum of 19 years.
Mr Xu, who was from China but had been staying with his daughter Diana, was left with 28 injuries to his head and neck as well as a laceration and bruising to his genital area, the court heard.
Richardson was seen dragging Mr Xu along the street but ran off when he was disturbed by witnesses shortly before 08:30 GMT.
Mr Xu was found wearing only a T-shirt and died in hospital.
Francis McEntee, prosecuting, said the motive for the assault remained a mystery.
Judge Brown said Mr Xu had been attacked "in a brutal, vicious and very cruel way."
"I am satisfied he suffered additional degradation when you removed his lower clothing and dragged him along the street," he said.
He said Richardson, who had been at a New Year's Eve house party, left his victim "dying in the gutter".
The court heard after the attack Richardson went to the house of friend Luke Jenkinson, 22, in nearby De Lacy Street, where he changed and washed his clothes.
Mr McEntee said friends had reported Richardson telling them he had "kicked and stamped" on Mr Xu's head.
The court heard Mr Xu's wife and daughter were unable to complete a victim statement as they were too distressed.
John Jones QC, representing Richardson, said he was "a young man with the most disadvantaged background and upbringing" who had been diagnosed with a personality disorder and learning difficulties.
Jenkinson was sentenced to two years and nine months after earlier admitting assisting an offender.
The court heard he did not know Richardson had murdered Mr Xu when he helped him.
A man who admitted murdering a 67-year-old jogger in a "brutal and cruel" attack has been jailed for life.