Eddie Nketiah scored twice as Arsenal set up an FA Cup fourth-round clash away to Manchester City after seeing off third-tier Oxford United 3-0 on Monday.
Mohamed Elneny's header opened the floodgates at the Kassam Stadium after the Premier League leaders failed to make the breakthrough for more than an hour.
Nketiah then sealed the win by taking his tally to four goals in as many games since the World Cup break.
Arsenal were dominant in possession before the break but struggled to create any clear-cut chances and were further frustrated by the decision not to award a penalty for handball when Elliott Moore blocked Albert Sambi Lokonga's effort.
Fabio Vieira was one of those not commonly in Arteta's starting line-up given a chance to shine and the Portuguese made his mark after the break with two assists.
The former Porto midfielder's inviting free-kick was headed in powerfully by Elneny for the Egyptian's first goal since 2021.
Nketiah then continued to make the most of his prolonged run in the side following Jesus' injury.
The all-time top goalscorer for England's under-21s coolly rounded Edward McGinty from Vieira's through ball to roll into an empty net.
Saka was then replaced after receiving treatment in concerning scenes for Arsenal, but there was some solace in the return of Emile Smith Rowe for the first time since September.
Nketiah added his second of the night with another cheeky finish as he dinked the ball over McGinty from Martinelli's pass 14 minutes from time.
A much tougher test awaits in the next round when the Premier League's top two will go head-to-head at the Etihad on the last weekend of January.
Liam Wheeler has provided the player ratings from the Kassam Stadium in the photo gallery above. To move on to the next photo, click on the arrows or swipe if using a mobile device.