Arsenal produced a statement win as Mikel Arteta's full-strength side thrashed Sporting 5-1 in Lisbon to boost their chances of automatic Champions League qualification.
Sporting once again started slowly against Premier League opposition in Europe, just as they did against Manchester City in Ruben Amorim's final home game, but Arsenal did not let them off the hook as their rivals had a few weeks earlier.
Arsenal punched in three first-half goals through Gabriel Martinelli, Kai Havertz and Gabriel to put the Gunners into what felt like an unassailable lead by the break thanks in large part to an inspired Bukayo Saka wreaking havoc down the right flank.
Sporting pulled a goal back less than three minutes after the restart, centre-back Goncalo Inacio turning in a corner at the front post, raising the possibility of an unlikely comeback, although those hopes lasted less than 20 minutes before Saka's penalty iced the game.
Substitute Leandro Trossard tapped in another on the rebound eight minutes from time after Mikel Merino's shot was parried by Sporting goalkeeper Franco Israel to put the result beyond doubt and move Arsenal into seventh, above their hosts on goal difference.
Sporting were torn apart in the first half, particularly down their left, where Jurrien Timber crossed in for Martinelli's opener inside 10 minutes before Saka set up Havertz for the second shortly after, with Gabriel heading in a Declan Rice corner for the third.
The home side's revival fell flat after Saka restored the three-goal lead from the spot, having seen his captain Martin Odegaard chopped down from behind by Sporting defender Ousmane Diomande, fortunate not to receive a second booking.
Arsenal, for the first time since August, were able to field their best team, starting Saka, Rice and Odegaard, and looked back to their imperious best. They now find themselves just inside the automatic qualification places in eighth with three games to go.
Arteta: We were exceptional
Mikel Arteta hailed the best away European performance of his reign as Arsenal claimed their biggest away win in the Champions League since beating Inter by the same scoreline in 2003.
"For sure, especially against opposition we played at their home who have not lost a game in 18 months - they have been in top form here - so to play with the level, the determination, the purpose and the fluidity we showed today, I am very pleased," said Arteta.
"The team played with so much courage, because they are so good. When I'm watching them live they are so good! They were all exceptional today. It was a big performance, a big win and we are really happy.
"The performance was there a few times when we have played big teams. That's the level that we have to be able to cope and you have to make it happen, and that creates belief."
Saka: This is where Arsenal belong
Arsenal forward Bukayo Saka, named player of the match, told TNT Sports:
"We spoke about it before the game. We know this season they've been a top team but we believe in ourselves and we just needed to be us.
"We played with confidence. Everyone was top and anyone could have got this [the player of the match award].
"I'm really proud of all the boys today. This is where we belong so we showed the level we can play at and we need to continue playing like this."
On his penalty: "It was important but I didn't really feel the pressure. I was confident."
On playing again with Martin Odegaard: "He's an unbelievable player. Today, he returned and you can see the big smile on my face.
"There's a chemistry we have, I enjoy playing with him. I'm happy he's back and I hope he stays fit for the rest of the season."
Analysis: Arsenal hitting form at the right time
Just as Manchester City's season descends into crisis, Arsenal are quietly rediscovering their best form. This win at Sporting, the first for any visiting side in more than a year, was a reminder of just how ruthless Mikel Arteta's side can be.
Arsenal's patchy form of the past month suggested there might be signs of mental fatigue in a squad that has been runners-up to Pep Guardiola's winning machine in the Premier League two years running. This performance dispelled those concerns.
Sporting were there for the taking but Arsenal put them away with relative ease to claim back-to-back wins for the first time since the first week of October. The Portuguese champions were never in the game.
Arsenal were dominant from start to finish, undoubtedly boosted by the return of their star trio, who have restored balance to a side that so often looked disjointed over the past month. They must be considered as contenders for all the top prizes - if they can stay fit.
City are on the slide and all eyes are on Liverpool in the title race. Arsenal may be nine points back but will feel time is on their side. Just as in the Champions League, they are right in the mix.