Keith Casey, 28, and co-accused Mark Kitching, 45, were seen by police running after the victim before punching him numerous times to the head.
He was knocked to the floor and suffered a fractured cheekbone and a broken nose.
Teesside Crown Court heard the late night attack was witnessed by members of the public.
Prosecutor Shada Mellor said two police officers were on patrol in the Furness Street area at around 11pm on January 14 this year when they saw Casey and Kitching chase the victim through the street.
She said: “They recalled [the victim] looked scared and appeared to be trying to evade the two males.
"They caught up to [him] and began repeatedly punching him to the head and face, the result being that [the victim] fell backwards on to the ground.”
Ms Mellor said the police got out of their car and intervened adding: “Members of the public were present and observed the attack.”
The victim was left with cuts to his face, a fractured cheekbone and broken nose.
Casey, who has 88 offences on his record, including for violence and public disorder, made no comment when questioned by police.
Both he and Kitching, of Mulgrave Road, Hartlepool, later pleaded guilty to causing actual bodily harm when a trial was due to happen at Teesside Magistrates Court in March.
Kitching was given 24 weeks prison suspended for two years with supervision in the magistrates court, a three-month night time curfew, and ordered to pay £500 compensation.
Casey, of Miers Avenue, was sent to the crown court to be sentenced due to his worse record, and was given jail.
His barrister Stephen Constantine, mitigating, claimed Casey had reacted to disparaging comments.
“It wasn’t pre-planned, it was something that occurred on the spur of the moment,” said Mr Constantine.
He added Casey had been engaging well with the probation service and other professionals until shortly before the attack.
He was jailed for 28 weeks by the Recorder of Middlesbrough Judge Paul Watson QC.
Judge Watson said: “You attacked this man together with another and you caused him, what in my view, were serious injuries.”