Lankshear’s fifth goal in the Championship – making him the division’s top scorer – came from an excellent low cross from right-back Callum Brittain that took out the defence and goalkeeper allowing the 21-year-old to score at the back post.
The striker could have had a second just before the interval but could not beat goalkeeper Charles.
QPR’s hopes were not helped by losing two key attacking players to injury before half-time as first Ilias Chair and then Richard Kone had to go off.
But one of their replacements, Rumarn Burrell, almost brought the Hoops level only to be denied by a big save from Radek Vitek.
Goalscorer Lankshear was withdrawn as Boro tried to regain control and substitute Conway had a great opportunity to make the points safe, but Charles saved the one-on-one opportunity with his leg.
QPR pushed their opponents back and thought they had levelled only for Vale’s effort to come back off the angle of post and bar as Boro defended for their lives.
In each of their last six away games in the Championship, the Teessiders had scored first and failed to win but they held on for a significance victory despite some late nerves.