Match ends, Middlesbrough 1, Sunderland 0.
Middlesbrough climbed to fifth in the Championship with victory over managerless Sunderland, who remain rooted to the bottom of the table.
Teenager Marcus Tavernier tucked in his first league goal from close range early on to give Boro victory.
Sunderland, who sacked boss Simon Grayson on Tuesday, created chances.
But home keeper Darren Randolph produced a fine double save to keep out Didier Ndong and Lewis Grabban, and denied Lee Cattermole.
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Boro, who made it four straight Tees-Wear derby wins for the first time since February 2003, had other openings too, with Britt Assombalonga, Martin Braithwaite and Stewart Downing all forcing saves out of Sunderland goalkeeper Robbin Ruiter.
However, 18-year-old Tavernier's neat finish from Braithwaite's cross on his full home league debut was enough to secure a third successive league win for Boro and extend Sunderland's winless run to 14 games.
That goal came moments after Randolph's superb reaction stop to deny Grabban after he could only push away Ndong's 25-yard drive, while Aiden McGeady twice fired off target for the visitors.
The Black Cats, who slipped to the foot of the table after Bolton beat Norwich on Saturday, have made the worst start of any side in the second tier who were relegated from the Premier League the previous season, taking just 10 points from their opening 16 games.
That record prompted American owner and chairman Ellis Short to admit on Friday that the club have "a bit of a crisis to solve right now", with Sunderland expected to replace caretakers Billy McKinlay and Robbie Stockdale with an experienced manager before the home game with Millwall on 18 November.
Middlesbrough boss Garry Monk told BBC Tees:
"Derbies aren't the prettiest games a lot of the time but the main thing is you win.
"The biggest moment of quality in the game was our goal, with the build-up and its execution, and if anything deserved to win the game, that bit of quality did.
"Marcus Tavernier will get stronger with time and experience but we've been delighted with him. He's deserved his chance and he's done very well, and today is a memory that will live with him forever."
Sunderland joint-caretaker manager Robbie Stockdale told BBC Newcastle:
"At some point this season we've got to make the big moments count in our favour and too many times this season we haven't done that.
"The keeper has made a fantastic save [from Grabban] and it could be a different game.
"I thought the shape of the team was good and I thought at time we looked a real threat, but the big moments have to be better from us."
- 22ChristieBooked at 63mins
- 7LeadbitterSubstituted forForshawat 85'minutes
- 62TavernierSubstituted forJohnsonat 64'minutes
- 9AssombalongaSubstituted forFletcherat 81'minutes
- 2da Silva
- 2JonesBooked at 17minsSubstituted forMatthewsat 27'minutes
- 36WilsonBooked at 75mins
- 17NdongSubstituted forHoneymanat 55'minutes
- 6CattermoleBooked at 44mins
- 19McGeadyBooked at 60mins
- 4McNairSubstituted forWilliamsat 77'minutes
- Jeremy Simpson
- Shots on Target
Second Half ends, Middlesbrough 1, Sunderland 0.
George Honeyman (Sunderland) wins a free kick on the right wing.
Foul by Adam Forshaw (Middlesbrough).
Jonathan Williams (Sunderland) wins a free kick in the defensive half.
Foul by Adam Forshaw (Middlesbrough).
Foul by George Honeyman (Sunderland).
Marvin Johnson (Middlesbrough) wins a free kick on the left wing.
Foul by Jonathan Williams (Sunderland).
Adam Forshaw (Middlesbrough) wins a free kick in the defensive half.
Marc Wilson (Sunderland) wins a free kick in the attacking half.
Foul by Ashley Fletcher (Middlesbrough).
Substitution, Middlesbrough. Adam Forshaw replaces Grant Leadbitter.
John O'Shea (Sunderland) wins a free kick in the defensive half.
Foul by Martin Braithwaite (Middlesbrough).
Substitution, Middlesbrough. Ashley Fletcher replaces Britt Assombalonga.
Attempt missed. Aiden McGeady (Sunderland) left footed shot from the left side of the box misses to the left. Assisted by Bryan Oviedo with a cross.
George Honeyman (Sunderland) wins a free kick in the defensive half.
Foul by George Friend (Middlesbrough).
Substitution, Sunderland. Jonathan Williams replaces Paddy McNair.