Nigel Clough’s Mansfield Town repeated their trick from last season, sealing a deserved victory as they resolutely defended a well-earned early lead.
The visitors benefited from a Lee Burge error to go ahead through Rhys Oates just minutes into the game, and after enjoying the better of the first half they dug in resolutely through the second.
Sunderland hit the bar through Dan Neil at the start of stoppage time, but were unable to work Nathan Bishop anywhere near enough through the contest.
Though Johnson had unsurprisingly shuffled his pack following a bruising week on the road, it was even with six changes a side more than strong enough to seal progression into the next round.
Mansfield had struggled in the opening weeks of the season but victory at Tranmere Rovers last weekend looked to have lifted their spirits, and it was little surprise given Sunderland’s recent travails that they found joy pressing early and aggressively.
Even if the opener was self-inflicted from the home side’s point of view, it came after a couple of lucky escapes.
The distribution from the back had been unconvincing in the first few minutes, to say the least, and ultimately gifted the lead to Clough’s side just five minutes in.
Burge tried to distribute to his centre back but instead laid it straight into the path of Oates, who looked certain to score. The finish was not emphatic but good enough, finding the far corner after striking the inside of the near post.
Sunderland were struggling to produce any kind of rhythm in possession, though showed that there were spaces to be found when Wright finally broke the press on the quarter of the hour mark. Cirkin drove forward and played a clever one-two with Elliot Embleton in the channel, but the cross to the back post was just too heavy for Dajaku who could only head high and wide.
That was an encouraging sign, but in truth the movement and precision exhibited in that move proved to be the exception, rather than the rule.
Mansfield were laying from a book that has yielded Clough success here before, happy to wait for the error in possession before breaking in numbers with strong runners from midfield.
It should have yielded a second when Broadhead was robbed near the halfway line, Mansfield suddenly having numbers on the overlap. The ball was quickly driven into the right-hand channel where Charsley met it on the run, his effort inches wide of the far post with Burge undoubtedly beaten.
Broadhead was at least attempting to show some drive in possession, but the decision to move Aiden O’Brien infield and Elliot Embleton onto the wing meant the Black Cats were again lacking composure in possession.
A similar move offered Charsley another opening shortly afterwards, but this time it was his first touch that let him down and allowed Burge to gather.
Sunderland did close to a response when Dajaku burst past his marker and stood up a cross, Bishop saving well from Broadhead’s header, but it rather summed up a listless half that the visitors would break and almost double their advantage immediately.
Lapslie saw an effort deflected just over the bar after meeting a low cross just inside the box, before Hawkins towered above his marker from the corner and planted a header off the crossbar.
The Black Cats were labouring, reflected starkly in a quadruple substitution from Johnson, the head coach making clear that he wanted a better tempo and considerably more personality in possession.
The speed of the game certainly lifted, though McLaughlin went close to making it two when a free kick ran to him and his effort flew just wide of the far post.
Sunderland did look sharper, though, and went close when Gooch played a pass inside and Neil struck it just wide of the far post on the half volley.
Mansfield continued to look a threat on the break, but the hosts were benefiting from a change of shape. Johnson had matched the visiting midfield diamond and with more ball players on the pitch, the errors in possession at least stemmed from a willingness to try and break open the defence.
The chances remained elusive, though, amid swirling winds and growing restlessness in the stands.
Though not as threatening as they had been in the first half, Mansfield were keeping their shape and looking disciplined.
It wasn’t until the final ten minutes that Sunderland finally carved a real opening of note, a good move down the right-hand side seeing Carl Winchester drive a threatening ball into the channel. The ball across to the back post was met by Evans, but his effort was blocked by the covering defender.
At last, the hosts were beginning to build some sustained pressure, pushing Mansfield into their own box and forcing poor clearances.
Clough’s side were able to reset and relieve some pressure, and though Neil struck an excellent effort off the bar at the start of stoppage time, they were able to hold on to the lead and seal the win.
Sunderland XI: Burge; Alves (Winchester, 45), Flanagan (Doyle, 45), Wright, Cirkin (O’Nien, 71); Evans, Neil (O’Nien, 72); Dajaku (Pritchard, 45), Embleton, O’Brien (Gooch, 45); Broadhead
Subs: Hoffman; Taylor, Younger, Harris
Mansfield Town XI: Bishop; Hewitt, O’Toole, Hawkins, McLaughlin; Maris, Charsley (Forrester, 90), Quinn, Lapslie (Sinclair, 84); Oates (Bowery, 62), Clarke
Subs: Johnson, Shelvey, Burke, Ward, Law
Bookings: Evans, 31 Hewitt, 48 Wright, 49 Charsley, 50 Clarke, 79 Quinn, 79