Despite some early pressure, the Black Cats took the lead when Edouard Michut scored his first goal for the club with 30 minutes played.
The hosts equalised on the stroke of half-time, though, when Manchester City loanee James McAtee found space in the box and converted with a low finish.
Another City loanee then scored the winner as Tommy Doyle’s free-kick went straight in just after the hour mark.
Here’s how Phil Smith rated the Sunderland players:
. Safc Sufc Roberts 1.jpg
Patrick Roberts playing for Sunderland against Sheffield United Photo: Frank Reid
. Anthony Patterson - 7
Distribution was short of its best but he made some excellent saves to deny Sheffield United at the end of a couple of very dangerous counters. 7 Photo: Martin Swinney
. Trai Hume - 5
Sheffield United felt he should have been sent off for a very late challenge in the first half but only a yellow was shown. It was probably a 50-50 call. Was steady enough after a tricky start. 5 Photo: Frank Reid
. Daniel Ballard - 6
Competed well and won a lot of headers and duels - little he could realistically do about either goal. 6 Photo: Frank Reid
. Danny Batth - 6
Like Ballard, had another steady game in which he made some good interventions. Sheffield United created chances but that was mainly as they broke through midfield. 6 Photo: Frank Reid
1. Anthony Patterson - 7
Distribution was short of its best but he made some excellent saves to deny Sheffield United at the end of a couple of very dangerous counters. 7 Photo: Martin Swinney
2. Trai Hume - 5
Sheffield United felt he should have been sent off for a very late challenge in the first half but only a yellow was shown. It was probably a 50-50 call. Was steady enough after a tricky start. 5 Photo: Frank Reid
3. Daniel Ballard - 6
Competed well and won a lot of headers and duels - little he could realistically do about either goal. 6 Photo: Frank Reid
4. Danny Batth - 6
Like Ballard, had another steady game in which he made some good interventions. Sheffield United created chances but that was mainly as they broke through midfield. 6 Photo: Frank Reid