U.K. Dean Smith, 46, launched the cowardly attack on Gary Hackney, 60, while he waited for a coffee shop shop to open outside a shopping centre at 8.45am on June 7.
A court heard the drug addict had been arguing with two men before he turned his attentions to the victim who had been minding his own business.
But when Mr Hackney tried to walk away from the altercation, the yob smashed him from behind with a metal chair and kicked him down a flight of steps.
Smith then stood on the elderly man's hand and made off with his phone, leaving him injured outside the Intu Shopping Centre in Hanley, Stoke-on-Trent, Staffs.
After being arrested unrepentant Smith bragged to officers how he had kicked his victim "just like Bruce Lee".
The loser was jailed for four years.
