Britt Assombalonga bundled Boro ahead in the first half, just his second goal in 13 games this season
Middlesbrough earned a clinical victory as managerless Derby County lost for the second time in a row under joint interim boss Wayne Rooney.
Britt Assombalonga poked the ball in from close range to ruin a bright start by the visitors and set the bottom-of-the-table Rams on their way to a fourth consecutive league defeat.
Player-boss Rooney, England's record goalscorer, moved further forward after the interval to try to provide a cutting edge and reward their territorial dominance.
Substitute Louie Sibley twice went close to grabbing an equaliser, only for a flowing move to end with Matt Clarke, under extreme pressure from Assombalonga, turning the ball into his own net to put Middlesbrough 2-0 ahead.
Boro, under their ever-wily 71-year-old manager Neil Warnock, then piled on further misery for disheartened Derby when Marvin Johnson curled in a delightful third home goal into the far corner.
And the hosts could have added to their tally on the way to a win that takes them up seventh in the Championship table.
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Defeat means Derby have only managed one win in 13 league games so far this season, scoring just five goals and not finding the net in four matches.
The scoreline was harsh on Rooney's side, but the experience and tactical nous of his counterpart won through.
Warnock, whose appointment by Boro in June saw him take charge of the 16th club of his managerial career, has now reached 1,509 games as a boss.
Warnock replaced Jonthan Woodgate as Boro boss
His side soaked up some solid Derby pressure in the early stages at the Riverside before taking the lead.
Assambalonga had the first chance of the game, a strike from the edge of the area that was well saved by Scotland keeper David Marshall.
The Rams, whose owner Mel Morris is on the verge of selling the club to Abu Dhabi-based Sheikh Khaled bin Saquer Zayed Al Nayhan, were on top thereafter, edging possession and looking neat and tidy.
But as in their first match under their caretaker coaching quartet against Bristol City following the sacking of Phillip Cocu, they lacked a telling threat up front and struggled to create chances.
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Tom Lawrence did well to fashion a strike for himself from 18 yards that was held by Marcus Bettinelli and Max Bird sent another shot from distance narrowly wide.
Sibley almost scored within 30 seconds of the restart, only to shoot just past the post and he went even closer with a decent low strike that forced Bettinelli into a scrambling save.
However, Boro, who have conceded a division-low six goals from their 13 games, made it 2-0 when Djed Spence played in Johnson on the left flank and his low cross was diverted in by Clarke.
There was still time for a third goal against an increasingly stretched defence, as Johnson showed poise and class to bend a beautiful strike into the far corner.
- Line-upsMatch StatsLive Text
Line-upsMiddlesbrough
- 1Bettinelli2Dijksteel6Fry17McNair27Bola16Howson22Saville7TavernierSubstituted forWingat 86'minutes19RobertsSubstituted forSpenceat 62'minutes18WatmoreSubstituted forJohnsonat 63'minutes9AssombalongaSubstituted forAkpomat 72'minutes
Substitutes
- 3Johnson8Wing10Akpom15Wood24Folarin29Spence32Stojanovic33Coulson
Derby
- 1Marshall12ByrneBooked at 53mins2Wisdom16Clarke26BuchananBooked at 65minsSubstituted forHolmesat 70'minutes8Bird32Rooney10LawrenceBooked at 49minsSubstituted forWhittakerat 74'minutes38Knight7JozwiakBooked at 9minsSubstituted forKazim-Richardsat 70'minutes9WaghornSubstituted forSibleyat 45'minutes
Substitutes
- 4Shinnie13Kazim-Richards17Sibley18Whittaker21Roos22Evans25Holmes33Davies39Stretton
Referee:Peter BankesMatch StatsHome TeamMiddlesbroughAway TeamDerbyPossessionHome37%Away63%ShotsHome10Away10Shots on TargetHome5Away2CornersHome4Away5FoulsHome11Away16Live TextPost update
Match ends, Middlesbrough 3, Derby County 0.
90'+4'Full Time
Second Half ends, Middlesbrough 3, Derby County 0.
90'+4'Post update
Foul by Jason Knight (Derby County).
90'+4'Post update
Marvin Johnson (Middlesbrough) wins a free kick in the defensive half.
90'+4'Post update
Offside, Middlesbrough. George Saville tries a through ball, but Marvin Johnson is caught offside.
90'+2'Post update
Foul by Colin Kazim-Richards (Derby County).
90'+2'Post update
George Saville (Middlesbrough) wins a free kick in the defensive half.
90'Post update
Foul by Duane Holmes (Derby County).
90'Post update
Marc Bola (Middlesbrough) wins a free kick in the defensive half.
88'Post update
Foul by Louie Sibley (Derby County).
88'Post update
Djed Spence (Middlesbrough) wins a free kick in the defensive half.
87'Post update
Jason Knight (Derby County) wins a free kick in the defensive half.
87'Post update
Foul by George Saville (Middlesbrough).
87'Post update
Corner, Middlesbrough. Conceded by David Marshall.
87'Post update
Attempt saved. Djed Spence (Middlesbrough) right footed shot from the right side of the box is saved in the centre of the goal. Assisted by Marcus Bettinelli.
86'Substitution
Substitution, Middlesbrough. Lewis Wing replaces Marcus Tavernier.
86'Post update
Attempt missed. Morgan Whittaker (Derby County) left footed shot from outside the box is high and wide to the left. Assisted by Duane Holmes following a corner.
85'Post update
Corner, Derby County. Conceded by Patrick McNair.
83'goalGoal!
Goal! Middlesbrough 3, Derby County 0. Marvin Johnson (Middlesbrough) left footed shot from the centre of the box to the top left corner. Assisted by George Saville following a fast break.
82'Post update
Offside, Middlesbrough. Chuba Akpom tries a through ball, but Marvin Johnson is caught offside.
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Source: bbc.com