Aidan Morris, the in-form Lankshear and a Lewis Brunt own goal meant the visitors were already 3-0 up in the first half before Canadian striker Thelonius Bair pulled a goal back in stoppage time.
But former Bolton loan favourite Amario Cozier-Duberry, who scored nine goals for the Trotters in League One last season, made the points safe for Boro in the 73rd minute.
Lankshear added a fifth five minutes later with his 11th league goal of the season - his sixth in six games.
Bolton's defeat could have been even heavier but for several fine saves by Republic of Ireland goalkeeper Gavin Bazunu.
Victory saw Boro climb above both Swansea and West Ham, who will each have the chance to go top on Saturday, with the Swans away to Queens Park Rangers and the Hammers at home to Southampton.
