Daniel Bassett, 22, claimed he had blacked out in the fight with his former friend Timothy Russell.
He was found guilty at Shrewsbury Crown Court of causing grievous bodily harm with intent.
Bassett admitted causing the injuries but denied the more serious charge of intent.
Mr Recorder Gareth Evans QC jailed him for six years saying he would have to serve half the sentence before being released on licence.
The court was told that the two men came to blows in St Georges, Telford, in July 2017.
Mr Russell was taken to the Princess Royal Hospital in the early hours of July 22, where it was discovered the lower part of his left earlobe was missing. He also had cuts to the bridge of his nose.
Bassett, of Holmes Avenue, Plymouth, had a black right eye, scratches and bruises.
He told the jury he blacked out in the fight, but accepted that he must have caused the injuries to Mr Russell. He said he had blacked out in the past and believed himself to have split personality disorder, although did not have a diagnosis.