Vincent Hill, 60, admitted sexually and indecently assaulting the boy at addresses in Paisley, Inchinnan and Erskine, all Renfrewshire.
The abuse began when the boy was aged 12 and lasted from 1998 until 2002.
The High Court in Glasgow heard that Hill was arrested in 2013 after his victim revealed the abuse to his wife.
Jailing him, judge Lady Scott told Hill he had "systematically abused" and "deliberately groomed" his victim.
The judge said the prison term would have been eight years, but for the guilty plea.
The court previously heard that the victim first got to know his abuser in 1997, when Hill worked as a market trader, selling computer games and consoles at a car boot market in Glasgow.
Prosecutor Shirley McKenna told how, in an attempt to keep the boy quiet, Hill would often take the boy to watch his favourite football team, Rangers.
The court also heard that the child lived a "chaotic life" - a factor Hill took advantage of.
Ms McKenna said the abuse had a "profound effect" on the victim, and had led to him attempting suicide and requiring counselling. It was said that this had led to an "impoverished" life.
The court heard Hill later sent a text to the victim claiming he wanted to "cut a deal" and that he would plead "guilty". Hill also claimed he was "sorry" and asked for the man to "forgive" him.
A man who groomed and abused a schoolboy then took him to football matches in a bid to buy his silence has been jailed for seven years.