Arsenal will enter the north London derby on Sunday on an even keel and, given their propensity for wild ups and downs, that should not be taken for granted. They have often seemed allergic to meeting the barest minimum expectation in recent years, so a third successive win will serve Mikel Arteta admirably, regardless of their opponents’ merits. Although it will be a distant memory by the time Spurs’ visit is dissected, a routine dismissal of AFC Wimbledon delivered enough to keep things ticking over, earning a fourth‑round tie against Leeds and guaranteeing more competitive action for at least some of the fringe players deployed here. The feeling was good enough for Arteta to linger by the touchline after completing his post-match broadcast interviews, posing for photographs and selfies with fans. He has long preached the need to forge connections with the support and those moments, brief though they might have been, were not a given either. Everyone had finished the night in high spirits, particularly after watching Eddie Nketiah cast off his forgotten-man status by scoring Arsenal’s third goal with a sublime backheel. “To have 50,000 fans in the Carabao Cup on a Wednesday night is pretty special and doesn’t happen in a lot of places,” Arteta said. Around a sixth of that figure had arrived in hope of a shock for the visitors, seventh in League One and clearly a well-drilled unit, but Wimbledon’s only chance of note arrived when Ethan Chislett missed a late header. Otherwise Arsenal exerted full control, although they ran through the gears only after Emile Smith Rowe and Bukayo Saka had been introduced in the second half. Until then they struggled to build on Alexandre Lacazette’s early penalty, awarded after Nesta Guinness-Walker had scythed Gabriel Martinelli down following a neat pass by Nketiah. Lacazette, who has only 31 minutes of Premier League football to his name this season, captained Arsenal but was quiet in general play. By contrast Nketiah was patently eager to please in his first senior action of the campaign. If he was overzealous in flattening the Wimbledon defender Henry Lawrence with an attempted overhead kick that was never on, he was classy in flicking Cédric Soares’s centre past Nik Tzanev 10 minutes from time to guarantee the reward he deserved. “Eddie gives us a lesson every day in how a professional should do his job,” Arteta said. “He gets his head down, trains harder than anyone, supports every teammate. I’m so happy for him.” Three minutes before Nketiah’s flourish Smith Rowe stabbed in Arsenal’s second goal from close range to settle a game that had been meandering. Smith Rowe had replaced Thomas Partey, who was the only survivor from the starting lineup at Burnley on Saturday. “We believe the rhythm of the matches is nothing like any training session, so he needed to play and it was very beneficial,” said Arteta of Partey, who is still reaching match fitness after injury but will be pivotal to Arsenal’s hopes against Tottenham and beyond. Partey could have scored but, with his final intervention before departing, saw Tzanev tip over his 20-yard shot. The rangy left-back Nuno Tavares also hit a post but otherwise Wimbledon were resolute until Saka, moments after arriving on the pitch to raptures, began the move Smith Rowe finished. It was all enough to leave Arteta, who resisted the urge to test youngsters such as the gifted Charlie Patino, feeling grateful for the latest tiny step in his revival plan. “Really important,” he said regarding the patch of momentum Arsenal have built up before facing their fiercest rivals. “Confidence rises, competition brings the best out of you when you have difficult moments. Credit to how [the players] have handled the situation and now they are obviously looking forward to what is our biggest game of the season.” It needed no grander billing; Arsenal will, at least, return here with a spring in their step.