Veteran striker Obidiah Tarumbwa, who was guilty of spurning countless scoring opportunities, put Bosso ahead in the 24th minute after ghosting in from the blind side to tap home an inviting Bruce Kangwa cross from the left.
However, celebrations from both the players and supporters were subdued as Highlanders had had a sluggish start, playing second fiddle to the visitors in the early stages of the game.
The former champions survived an early scare from the prison warders who could have taken the lead as early as the second minute, but an unmarked Michael Mageja opted to set up a teammate instead of directing his header at goal.