Boro were given a route back into the match when Britt Assombalonga converted from the penalty spot, but they could not find an equaliser despite eight minutes of added time being played.
Relive how the 90 minutes of action unfolded in West Yorkshire with Sports Mole's live text coverage below.
STARTING XI: Lonergan; Ayling, Cooper, Jansson, Berardi; Vieira, Phillips; Saiz, Hernandez, Alioski; Roofe
SUBS: Wiedwald, Pennington, Anita, O'Kane, Sacko, Ekuban, Grot
STARTING XI: Randolph; Roberts, Ayala, Gibson, Friend; Howson, Leadbitter; Downing, Braithwaite, Tavernier; Assombalonga
SUBS: Konstantopoulos, Fabio, Fry, Traore, Johnson, Forshaw, Fletcher
Thomas Christiansen: "The target for Boro is the direct (automatic) promotion and they started bad but are in a good run now, just the opposite to what we did," he said in his pre-match press conference. But again, we are only three points away from each other and that can turn. Boro are a very good team, an organised team who know what they do with quality. But we know also where their weaknesses are, this is what we have to play with and of course we have to make it a tough game on Sunday. I think the players know the importance of the game, the three points that we need and I also believe we deserve but it's not coming alone, we need to work hard for it. The coach was here last year, let's see how the reception will be but it's still the players on the pitch who have to deliver the job."
Garry Monk: "If I'm honest about it - the way I look at it - I know outwardly the question will always be there because I was the manager of Leeds last season but this game's not about me, it's about my team. That's all I'm focused on and what my players are focused on but I totally understand why that question is there. Of course, in terms of my memories of Leeds, [I have] fantastic memories of Leeds. Last season we took a club that was very fractured in terms of relationships throughout certain departments and how it was as a club from fans to the team and we put foundations [in place]. Us, along with the fans, worked very hard to build that relationship to where it was strong and where it was together and unified. That side of it I'm very proud of."
LEEDS UNITED SUBS: Wiedwald, Pennington, Anita, O'Kane, Sacko, Ekuban, Grot
MIDDLESBROUGH SUBS: Konstantopoulos, Fabio, Fry, Traore, Johnson, Forshaw, Fletcher