Jack Ross was always confident that the defensive work being put in on the training ground at the Academy of Light would pay off.
The Scot and his coaching staff have been consistent in their approach since taking charge this summer and the Black Cats are now reaping the rewards.
Sunderland only managed one clean sheet in their opening 12 League One games but have now recorded four on the spin.
Victory over Plymouth Argyle, coupled with Peterborough United's defeat at Wycombe, saw Sunderland climb into the automatic promotion places.
They remain three points off leaders Portsmouth, who are showing no signs of dropping their standards, but Sunderland have a game in hand.
Keeping it tight at the back has been a big factor behind the club's five-game winning streak and it helps having the best goalkeeper in the league in the shape of Jon McLaughlin.
What does Ross put the change in fortunes regarding keeping clean sheets down to?
Ross said: "The work has been consistent and continuous, a little bit of that was making slight adjustments but also continuing to believe in the work we had been doing.
"I never felt like we had been cut open often in games before.
"We defended really well throughout the game, it was last-ditch stuff at times and Jon [McLaughlin] making saves.
"Naturally when you get a reward like a clean sheet then the belief begins to grow as well."
The back four were not shielded by Lee Cattermole at Home Park, the experienced midfielder was missing with a foot injury that will likely keep him out of the FA Cup tie at Port Vale.
Dylan McGeouch again stepped up to the plate, his best performance yet in a red and white shirt and a growing influence in this Sunderland side.
Defensively he was very disciplined, making several smart blocks, while he is cool, calm and collected on the ball, passing with intelligence and rarely wasting possession.
Competition for places is fierce at Sunderland and none more so than in central midfield.
Ross said: "I have been lucky this season, every time I have had to ask questions of the squad then every single one of them has taken their chance.
"Dylan's performances have been steadily improving, he showed what an influence he can be on the game.
"I am delighted as it helps heighten that competition for places.
"Luke O'Nien too, every time he has come on to the pitch he is having an impact on the game and did so again by winning the penalty."
Sunderland now have a break from League One action with the FA Cup first round trip to Port Vale next Sunday followed by the final Checkatrade Trophy group game away at Morecambe the following Tuesday.