Arsenal was given a scare by the Swedish upstart, but Sead Kolasinac's goal provided the breathing room necessary to advance.
Arsenal edged closer to the Europa League final with a 4-2 aggregate victory against Swedish side Östersunds FK, despite the away side claiming a historic victory at the Emirates on Thursday.
The travelling side found themselves deservedly 2-0 up at half-time - scoring two goals in 69 seconds - and giving Arsene Wenger's side an early scare. However, two minutes into the second half, Sead Kolasinac pulled a goal back after a missed clearance with a powerful right-footed shot straight into the back of the net.
Arsenal welcomed their visitors to the Emirates Stadium with a 0-3 aggregate lead. Many thought the tie was polished off following the first leg result, but it very much proved not to the the case.
Jack Wilshere made a start as Arsenal captain and Danny Welbeck lead the line for the Gunners, but the away team caused an early stir with their quick-succession goals.
Östersund manager Graham Potter bravely chose to start with two wide wingers, hoping to find a footballing miracle. They brought along 5000 fans along with them, which is 10% of the entire town's population.
Arsenal were left silenced early in the match as the visiting team started brightly, pacing forwards towards David Ospina's goal, pressing the home side and dispossessing them at any opportunity.
In the 22nd minute, the hard work paid off for the away team. Östersund winger Aiesh set away down the left-hand side of the box before slotting the ball across Ospina's goal. The ball may have taken a slight deflection off Calum Chambers into the back of the net, but the credit and hard work has to go to Aiesh.
Just 69 seconds later, the 5,000 Ostersunds fans had just regained their breath from the first goal, when Alex Iwobi sloppily gave the ball away in the middle of the park. Winger Ken Sema - who had been a bright spark for his side - showed off his power, held off Chambers with a lovely piece of footwork and rifled the ball home. This was not going to plan for the hosts.
Halftime couldn't have come at a better moment for the home side, who desperately needed to regroup if they were to progress further in the competition.
They got their goal early in the second half though, as Hector Bellerin placed the ball into a player packed box. A poor clearance from Ronald Mukiibi allowed the ball to fall to Sead Kolasinac's feet, and he took a light first touch before smashing the ball from close range into the back of the net.
Arsenal continued to search for the second goal of the night, with Welbeck's header coming close in the 69th minute but falling straight into the arms of goalkeeper Aly Keita. But the Östersund players played their part in this brilliant victory, leaving the 5000 fans with unforgettable memories from the Emirates.
Arsenal's victory means they advance into the last 16 of the Europa League as the only British side as Celtic were knocked out early in the day.
The Gunners now focus on their Carabao Cup final against Manchester City on Sunday hoping to win their first trophy of the season.