Cristhian Stuani scored two brilliant goals as Middlesbrough earned a 2-1 win over Sunderland in the Wear-Tees derby at the Stadium of Light, with David Moyes' injury problems continuing to pile up.
After his 25-yard stunner flew past Sunderland goalkeeper Vito Mannone in the 13th minute, Stuani rounded off a neat team move before the interval to inflict defeat upon Moyes in his first home match in charge.
Moyes' concerns will be even greater after the loss of John O'Shea to injury in the first half, his exit further stretching a squad already depleted by the enforced absences of Sebastian Larsson, Jan Kirchhoff, Lee Cattermole, Billy Jones and Lamine Kone.
And following the departure of Younes Kaboul to Watford and a back injury to Kone, the Sunderland boss deployed a new centre-back partnership of Papy Djilobodji - the Chelsea loanee making his debut - and O'Shea, while Paddy McNair operated in midfield.
While the hosts found it difficult at both ends, Middlesbrough, and in particular Stuani, were clinical with the chances that came their way.
Sunderland stepped up a gear in the second half and finally got the better of Boro keeper Brad Guzan - in for Victor Valdes who missed out with a hamstring injury - when his spill was poked home by Patrick van Aanholt.
However, despite being visibly rattled by the strike, Boro managed to hang on for the three points and their first win since returning to the top flight.
Aitor Karanka replaced Albert Adomah with Stuani in one of three changes from the 1-1 draw with Stoke City last weekend, and it quickly paid dividends.
Stuani was not closed down by Van Aanholt and used the opportunity to rifle a sensational 25-yard strike into the top-left corner.
It was a blow for Sunderland having been in control until that point, and although they regained their grip on the game the hosts found it difficult to break down the Boro defence.
Moyes had to replace the injured O'Shea with debutant Steven Pienaar in the 37th minute, Jack Rodwell subsequently dropping into the centre of defence.
And Boro added to Sunderland's woes on the stroke of half-time, Adam Forshaw sliding an excellent pass into the box for Alvaro Negredo who showed great composure to cut inside and square for Stuani to round off an excellent move with his second.
Sunderland were booed off at half-time but started to the get the fans back onside and Van Aanholt's low shot from the left-hand side of the box was parried behind by Guzan after 60 minutes.
The pressure continued to build and, after Jeremain Lens and Jermain Defoe had efforts blocked, it paid off in the 71st minute when Van Aanholt pounced after Guzan spilled Duncan Watmore's 20-yard shot.
Adnan Januzaj came close to marking his first Sunderland start with a goal, but the hosts - for whom late substitute Joel Asoro became their youngest Premier League player - were unable to find an equaliser before the final whistle.