A Charlie Wyke header put gloss on the score but it was January signing Ross Stewart that changed the game. He went close on a couple of occasions before finally lobbing Toby Savin to give Sunderland the lead.
Accrington offered little response and Wyke was able to seal the win from a corner to keep Sunderland a single point off the automatic promotion places.
Story of the game
Lee Johnson was forced into making five changes from Sunday's Wembley victory over Tranmere Rovers. Tom Flanagan came off during that game and will be out for at least a month, so Conor McLaughlin who replaced him on Sunday continued at centre back in a back three.
Dion Sanderson and Carl Winchester were cup-tied for Sunday's game and returned to the starting line-up replacing Josh Scowen and Grant Leadbitter. Jake Voskins came into the lineup on his 21st birthday replacing Callum McFadzean who fell to the bench.
It took a while for the game to settle into a pattern, the ball spent a lot of time in the air early on. Sunderland had attacking intent and pressed Michael Nottingham into a mistake.
Charlie Wyke and Aiden McGeady pressured him, the former came away with the ball and fed Wembley goalscorer Lyndon Gooch on the right wing. He cut inside onto his left but his shot was tame and comfortable for Toby Savin in the stanley goal.
It was the only chance of a dire opening 20 minutes. The hosts struggled to get a foot hold in the game and Sunderland were struggling to play their passing game on the chewed up pitch.
The biggest threat was Voskins down Sunderland's left, not having to do as much in defence he was dangerous going forward whipping a couple of crosses in but the likes of Wyke were struggling to get anywhere near them.
Accrington were defending well, the two previous meeting at the Wham Stadium had both ended 3-0 to Sunderland with Aiden McGeady scoring on both occasions. Accrington were going in strong on him everytime he even looked like having a second of space.
He won a free kick by the left hand byline and took it himself but it was an easy save for Savin.
It took until the 23rd minute for a clear cut chance. McGeady found Diamond who could have passed to Max Power but decided to take it on himself cutting inside from the right onto his left foot and curling an effort that Savin was forced to parry round the post and away from Wyke lurking for the rebound.
Accrington's threat was exclusively from set pieces, they were forcing scrambles in the Sunderland penalty area, they just couldn't connect to force Lee Burge into a save.
Sunderland caused panic with a cross of their own. McGeady's corner initially looked to be easily cleared by Dion Charles’ head but he nearly dinked his own goalkeeper but luckily for Stanley it went over the bar. From the resulting corner after a tussle in the box, Lyndon Gooch fired over.
Sunderland were nearly punished on the break, Winchester's shot on the edge of the Accrington box was blocked and the hosts broke with speed through Paul Smythe. He was one on one with Voskins and the Southampton loanee did well to force him wide so that he could only drag his shot across goal. It was a warning of why Accrington are in the playoff chase.
The best chance of the half came after 40 minutes, Gooch on the right cut onto his left and floated a cross over the Accrington defence, Luke O'Nein up from the back found himself free eight yards out in the box but could only put his header wide. He will have been furious he didn't do better and will know he should have at least forced a save from Savin who would have done well to react.
Sunderland were certainly the better team but will have been disappointed they were unable to put a spell of play together. They will have been glad that Harvey Rodgers put his header wide in first half stoppage time with the goal at his mercy.
There was an air of frustration for Sunderland at the half, shown by Lee Johnson's remonstrations to the referee as the players left the pitch.
The start of the second half saw a Sunderland debut for Ross Stewart, signed in January from Ross County. It meant a change of system to a 4-4-2 with Wyke and Stewart forming a partnership that Lee Johnson hoped could change the game.
The Scot nearly had a debut goal after three minutes. He got on the end of a McGeady free kick, leaping well but the header looped over the bar.
As for Accrington, Smythe was proving a nuisance getting himself in the faces of Sunderland's defence. His pressing forced a turnover in possession, Rodgers picking up the ball and feeding David Morgan but he fired just wide of Lee Burge's post.
Accrington tails were up and they went close again, Adam Phillips with an ambitious volley from the edge of the box, but it went just over the bar.
Stewart was offering something different for Sunderland and looked dangerous especially in the air. He got his just rewards 16 minutes into his Sunderland career. Gooch put a deep ball into the box and Stewart on the penalty box looped a header over Savin who will feel he should have done better.
Sunderland nearly repeated the trick moments later. Again Stewart rose well and knocked on a header to Wyke in behind. Savin came out to meet him, falling to the ground Sunderland's number nine managed to hook it over the keeper but it didn't have enough on it and a recovering defender easily cleared.
Sunderland were happy to sit on the lead and invite Accrington onto them but the hosts offered little going forward. Their main threat was still from set pieces but Sunderland were always managing to clear the ball before anything could come of it.
It looked like Sunderland had given up attacking, happy with their one goal but they put gloss on the score after 86 minutes. From a corner similar to a week earlier at Portsmouth it was all too easy for Charlie Wyke to escape his man and head in from close range to add gloss to the score and secure the three points.
Man of the match - Ross Stewart
Sunderland were bang average in the first half and it wasn't until the introduction of the former Ross County man that the game swung. He was excellent in the air, winning most things and did well to get his goal. He will struggle to dislodge Wyke in the starting lineup but he looks a strong option off the bench.