Mikel Arteta's troops failed to muster a single shot on target in the first leg and travelled back to North London reeling from a 1-0 defeat, where Galeno's injury-time stunner propelled Porto to an unforeseen triumph.
As a result, the Gunners are potentially just 90 minutes away from an eighth consecutive last-16 exit from the Champions League, but they have previous when it comes to reversing deficits against the Dragons.
Here, Sports Mole takes an in-depth look at the head-to-head record and previous meetings between the two sides.
Head-to-head record
Previous meetings: 7
Arsenal wins: 3
Draws: 1
Porto wins: 3
February's battle at the Estadio do Dragao marked the seventh Champions League battle between Porto and Arsenal, whose exceptional goalscoring exploits meant nothing in the first leg, and they were punished for their lack of guile right at the death of that one-goal loss.
Mere seconds after Galeno's exquisite curler nestled into the bottom corner, Porto rejoiced in beating Arsenal for the third time in their history, although all of those triumphs have come on home territory; it has been a completely different story for the Dragons in North London.
Indeed, Porto took a 2-1 lead to Arsenal for the second leg of their last-16 tie in the 2009-10 season, which Arsene Wenger's men overturned emphatically with a 5-0 win, where Nicklas Bendtner struck a hat-trick alongside efforts from Emmanuel Eboue and Samir Nasri, whose name is now best not mentioned inside the Emirates walls.
History is therefore on the hosts' side this week, as that five-goal pummelling of Porto marks the most recent time that they advanced beyond the last 16 of the Champions League, where they have consistently proven a class above Porto in North London.
Prior to their inaugural knockout battle, the two clubs clashed in the group stage of the 2008-09 and 2006-07 tournaments, the former of which saw Robin van Persie and Emmanuel Adebayor net braces in a 4-0 Arsenal home victory before Porto prevailed 2-0 on their own turf.
September 2006 saw the two outfits go head-to-head for the first time, and the Gunners had a Thierry Henry masterclass to thank for that 2-0 win, as the Frenchman registered both his final Champions League goal and assist (for Aleksandr Hleb) in Arsenal colours, before Porto dug in for a goalless draw a couple of months later.
Current Dragons captain Pepe played in both of those battles almost 18 years ago, and the veteran Portuguese was central to his side's clean sheet in the 2023-24 first leg, but Porto head to the Emirates having lost all three away games against Arsenal by an aggregate score of 11-0.
Thanks partially to those three defeats, the visitors have not managed to win any of their 22 European games in England at any level - losing 19 of them and only holding out for three draws - and failure to buck that trend on Tuesday would leave Porto vulnerable to another Arsenal turnaround.
Previous meetings
Feb 21, 2024: Porto 1-0 Arsenal (Champions League Round of 16)
March 9, 2010: Arsenal 5-0 Porto (Champions League Round of 16)
February 17, 2010: Porto 2-1 Arsenal (Champions League Round of 16)
December 10, 2008: Porto 2-0 Arsenal (Champions League Group Stage)
September 30, 2008: Arsenal 4-0 Porto (Champions League Group Stage)
December 6, 2006: Porto 0-0 Arsenal (Champions League Group Stage)
September 26, 2006: Arsenal 2-0 Porto (Champions League Group Stage)
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