Viktor Gyokeres' brace helped fire Arsenal to their first Premier League home win in 39 days. Say it quietly but it might just be one of their most important yet.
Martin Zubimendi was also on target to send the Gunners nine points clear of Manchester City before their awkward trip to Anfield.
The fact Aston Villa, the last top-flight team to lose at the Emirates on December 30, also dropped points at Bournemouth was also an added bonus.
Arsenal did not need to set the world alight but they were effective and comfortable without absent duo Bukayo Saka and captain Martin Odegaard to take another positive step towards the finish line.
They also recorded their third successive clean sheet on an afternoon which was somewhat soured by the sight of Leandro Trossard being forced off with a potential fitness issue late in the second half.
From the first whistle, Sunderland - still yet to record an away victory at Arsenal in the Premier League era - were out to frustrate the Premier League leaders by any means necessary.
FOLLOW OUR ARSENAL FB PAGE! Latest Gunners news, analysis and much more via our dedicated Facebook page
The Black Cats pressed in packs and attempted to rough up David Raya from set-pieces. Stand-in skipper Trai Hume nearly endured a moment to forget, however, when he almost sliced Noni Madueke's cross into his own net.
Pumped Sunderland frontman Brian Brobbey wrestled with William Saliba before leaving a late challenge on Zubimendi.
The thunderous tackle, which infuriated Mikel Arteta, earned the Dutchman a booking before Zubimendi dusted himself off and fired home the opener just one minute later.
The Spaniard met Trossard's pass first time and unleashed a low shot from 20-yards which flew into the bottom corner after kissing the inside of the post.
Zubimendi was signed from Real Sociedad to dictate play and tick the ball over from deep but this is now officially the best goalscoring season of his career (six in all competitions) and only Gyokeres (eight) has netted more for Arsenal in the Premier League than the defensive midfielder's five.
The 27-year-old also dedicated his goal to compatriot Mikel Merino, who is facing four months out after fracturing a bone in his foot, by replicating his compatriot's celebration.
Arsenal were then awarded a penalty after Gabriel Jesus was bundled over in the box but the Brazilian was later flagged offside following a VAR review - even though both of his feet were inside his own half when he first started his run.
Jesus' upper body was narrowly inside Sunderland's half, though unfortunately Liam Rosenior was not on the touchline to inform the officials.
Long shots became a theme of the first half as Declan Rice and Kai Havertz both curled narrowly wide before Sunderland saw a penalty shout ignored after ex-Gunner Dan Ballard went to ground from a dead-ball under the challenge of the £105m England international.
Raya did well to palm Chemsdine Talbi's awkward low strike away from danger just after the restart before Arsenal doubled their advantage through substitute Gyokeres.
Five minutes after coming off the bench, the Swede controlled Havertz's pass before slipping and stabbing his shot through the arms of Sunderland goalkeeper Robin Roefs.
He wasn't finished there though and doubled his tally deep into stoppage time after Gabriel Martinelli raced through and unselfishly squared around Roefs.
Six of Gyokeres' eight Premier League goals have now come against newly-promoted sides.
