Match ends, Middlesbrough 1, Rotherham United 0.
Stewart Downing's first-half goal secured a third successive Championship win for Middlesbrough at the expense of bottom club Rotherham United.
Downing intercepted a loose pass near the halfway line and raced into the penalty area before sending an angled shot past Millers goalkeeper Lee Camp.
Boro's Carlos de Pena hit the bar with a header from David Nugent's cross and George Friend hit the post late on.
Rotherham's Jordan Bowery came closest to an equaliser but fired wide.
The Millers have taken one point from five games since Neil Redfearn was appointed manager in October.
Middlesbrough held on for victory despite a subdued display and remain fourth in the table, a single point behind new leaders Hull.
England international Downing, making the 400th league appearance of his career, netted his third goal of the season to put Boro in front after 16 minutes.
De Pena and Albert Adomah went close to doubling their lead before half-time, while captain Grant Leadbitter's header was kept out by Camp after the break.
After Friend struck the upright with a powerful shot, substitute Diego Fabbrini failed to find the target from Emilio Nsue's cross.
Paul Green's effort from 25 yards before the break was Rotherham's only shot on target in the match.
Middlesbrough manager Aitor Karanka:
"It is a tough game but we missed chances to score the second, the third, the fourth.
"But we have to learn from this game, when everybody was expecting the second goal we played worst.
"The first goal is always the most difficult, we thought getting more was going to be easier and it was the opposite.
"Last season we lost a lot of points against teams at the bottom and this season we are winning them."
Rotherham manager Neil Redfearn:
"It was a vast improvement, at times we played really well.
"They are a good side. At times they created chances and they could have had another goal, but we also had our chances.
"But it's not the Middlesbroughs of this world where we need to get the results, this top six is by far and away ahead of the rest but it was a really diligent and tough performance."
- 7LeadbitterSubstituted forFabbriniat 79'minutes
- 10De PenaSubstituted forZuculiniat 65'minutes
- 23ThorpeBooked at 53mins
- 24AndreuSubstituted forMaguireat 87'minutes
- 19Clarke-HarrisSubstituted forNewellat 63'minutes
- 9WardSubstituted forBoweryat 73'minutes
- Paul Tierney
- Shots on Target
Second Half ends, Middlesbrough 1, Rotherham United 0.
Corner, Middlesbrough. Conceded by Harry Toffolo.
Fernando Amorebieta (Middlesbrough) wins a free kick in the defensive half.
Foul by Joe Newell (Rotherham United).
Attempt missed. Stewart Downing (Middlesbrough) right footed shot from the left side of the box is high and wide to the right. Assisted by Bruno Zuculini.
Attempt missed. Diego Fabbrini (Middlesbrough) right footed shot from the right side of the box misses to the left. Assisted by Emilio Nsue Lopez with a cross.
Substitution, Rotherham United. Chris Maguire replaces Tony Andreu.
Attempt missed. Diego Fabbrini (Middlesbrough) right footed shot from the centre of the box is close, but misses to the right. Assisted by Emilio Nsue Lopez with a cross.
Foul by Adam Clayton (Middlesbrough).
Grant Ward (Rotherham United) wins a free kick in the attacking half.
George Friend (Middlesbrough) hits the left post with a left footed shot from the left side of the box. Assisted by Stewart Downing.
Attempt missed. David Nugent (Middlesbrough) right footed shot from outside the box is too high.
David Nugent (Middlesbrough) wins a free kick in the attacking half.
Foul by Farrend Rawson (Rotherham United).
Attempt missed. Jordan Bowery (Rotherham United) right footed shot from the right side of the box is close, but misses to the right.
Substitution, Middlesbrough. Diego Fabbrini replaces Grant Leadbitter.
Corner, Middlesbrough. Conceded by Frazer Richardson.
Attempt saved. Grant Leadbitter (Middlesbrough) header from the centre of the box is saved in the top left corner. Assisted by Emilio Nsue Lopez with a cross.
Foul by Adam Clayton (Middlesbrough).