The Gunners stole the show in the first round of group stage fixtures in this season's UWCL, with Chelsea also victorious in France.
Lyon, the eight-time European champions and current holders of the Women's Champions League title, had never conceded more than four goals at home before this week.
On Wednesday, Arsenal came along and not only smashed that record, but also inflicted a biggest-ever defeat in this competition on the side that has dominated it for so long by winning 5-1 in France.
It was the headline result from the first round of group stage fixtures in this 2022-23 season, which wasn't without incident elsewhere, either.
Whether it was Barcelona hitting Benfica for nine, Chelsea leaving Paris with three huge points or Roma getting their first ever win in the Champions League proper, there was plenty going on across matchday one.
With 28 goals scored and plenty of history made, GOAL picks out the winners and losers from a crazy two days…
GettyWINNER: Jonas Eidevall
When the team news came out for Arsenal's game away at Lyon, it required a double-take. Vivianne Miedema, the Gunners' star player, was on the bench.
With Miedema deployed in midfield under Jonas Eidevall and that area needing some defensive reinforcement against the reigning champions, it was a sensible decision.
Playing Stina Blackstenius instead of the Dutchwoman as a centre-forward made some sense, too, as the Swede's movement off the shoulder and in behind the depleted Lyon defence would cause the hosts problems.
However, had Arsenal lost the game, it would no doubt be a stick to beat the coach with; a choice to be scrutinised. It was extremely bold in a huge game against top opposition – but it paid off.
Frida Maanum, who came in for Miedema in the middle, had perhaps her best game in an Arsenal shirt, while Blackstenius was exactly the threat Eidevall would've wanted.
It was no bad reflection on Miedema herself, just simply an excellent performance by the coach on a night where his tactical decisions were brilliant and his well-prepared game plan was wonderfully executed by his players.
AdvertisementGettyLOSER: Lyon
A biggest ever defeat in Europe. The most goals ever conceded in a home game. A result that matched the club's worst ever defeat in any competition. Wednesday was a record-breaking day for Lyon – and not in the manner they have become so used to.
It is a concerning scoreline for a number of reasons. First of all, it is one that every club in Europe will take note of, so if and when they come up against Lyon, they will look at Arsenal's display to see how to beat this formidable side.
Secondly, it comes in a 'group of death'. Juventus, whom OL only beat by one goal in last year's quarter-finals, are also in this pool. Most games will be tight, so such a heavy defeat could have even bigger repercussions than usual.
However, this historic loss also exposed how badly this team is missing key players. For starters, Lyon have just two fit senior centre-backs.
They are also missing 2018 Ballon d'Or winner Ada Hegerberg and the generational talent of U.S. women's national team star Catarina Macario – among many others.
With a large handful of those absentees not expected back for a few months, it is a worrying situation to be in.
Now, it's up to head coach Sonia Bompastor to do the best she can with those available to navigate what will no doubt be a tricky path out of this group – if she can find it.
GettyWINNER: Ingrid Engen
It's been a tricky start to life in Barcelona for Ingrid Engen, Norway's talented defensive midfielder.
She arrived in Catalunya last summer after a wonderful final season with Wolfsburg, having proven herself one of the best players in her position, and spent her first year at the club getting to grips with the Barca style.
However, just last month, the club paid a world-record fee for another excellent performer in that role – England's Keira Walsh.
It means Engen's competition for a place in the team is even tougher and that opportunities to show what she can do are even more important to take.
On Wednesday, she got one of those, starting against Benfica. Her display might not have been the headline-maker in a 9-0 victory, but it was quietly impressive and extremely tidy.
It was a reminder of why Barca signed her, what she can bring to the team and, all in all, her quality.
GettyLOSER: PSG's attack
It's been a difficult start to the season for Paris Saint-Germain, a team dealing with the long-term absence of star striker Marie-Antoinette Katoto, while getting used to the ideas of a new coach and integrating a number of new players.
France international Kadidiatou Diani was picked out by Chelsea captain Magdalena Eriksson as one of PSG's biggest threats before the two met on Thursday, and she has been in great form to make up for Katoto's spell on the sidelines so far this term, scoring four goals in five league games and two in three in Europe.
However, it was particularly apparent on matchday one of the UWCL group stage just how much she is missing her injured team-mate, a player she has formed such a deadly partnership with over the years.
So often those combinations between the PSG attackers were off-key on Thursday and in a game of few chances, it was even more apparent.
That Lieke Martens was also missing through illness was another blow on this occasion, but that chemistry between the forward players will need to develop quickly if the French side are going to unlock the goals required to escape one of this season's toughest groups.