When Arsenal visited Manchester City last season Erling Haaland let down his hair and showed that the champions were still head and shoulders above their challengers.
That 4-1 defeat was a reality check for Mikel Arteta’s men and effectively a fatal blow to their hopes of taking the trophy back to north London for the first time since 2004.
They would finish five points behind treble winners City, having won just three of their last nine games, as injuries exposed a lack of depth in their overstretched squad.
In that context, it is difficult to overstate the significance – both mathematically and symbolically – of Arsenal’s return to the Etihad Stadium on Easter Sunday.
Another City win would lift them two points above the Gunners with nine games left to play and lend weight to claims that Arteta’s side run out of fuel in the home straight.
But should the visitors end a seven-match losing run in the blue half of Manchester they will keep their noses in front, while a first win there since 2015 would keep them top of the table – and send out an unmistakable message.
However, Sunday is just the beginning of a make-or-break month for Arsenal’s hopes of ending their long wait to win a 14th domestic league title.
Starting with City, they are scheduled to have nine fixtures in the space of just 29 days. Those figures could even swell to 10 in 31 days if they progress in Europe.
It is their most demanding sequence of the season so far, by some distance, and promises to be a stern examination of their credentials.
But it is not just the quantity of games that looks daunting; it is also the quality of opposition that Arsenal will face.
Manchester City v Arsenal on Easter Sunday promises to shape the Premier League title race
Of their seven Premier League matches in that stretch, three are against teams in the top five and all but one are in the top 11.
In among all that is a two-legged Champions League quarter-final with Bayern Munich which has the potential to reopen the scars of chastening evenings past.
It is just as well that Arsenal will have had almost three weeks off by the time they face City on Sunday, meaning that players have had time to recharge, international duty notwithstanding.
Their busiest spell so far this campaign came in December, when they played eight times in 30 days. It coincided with their worst run, gleaning just three wins and three defeats.
But a concerted break which included a trip to Dubai that followed in January has been credited with reviving their season. They have won all eight league games since, scoring 33 goals.
Squad depth – particularly in defence – has cost Arsenal dear in the last two run-ins but, while questions remain, they look better equipped to handle any enforced absences.
The return to fitness of Takehiro Tomiyasu, Thomas Partey, Jurrien Timber and Gabriel Jesus means they have quality cover in all positions.
The Champions League is a potential complication, not just for the extra workload that it entails. Arteta is yet to show he can successfully juggle challenges on multiple fronts.
Then there is Liverpool, the third team in what is the most exciting Premier League title race for at least a decade, who could yet out-pace both of their rivals in the run-in.
All that could be rendered academic if City dish out another lesson on Sunday. Survive or even thrive at the Etihad, however, and it can galvanise Arsenal for a decisive month ahead.
Arsenal’s make-or-break month
31 March: Man City (A)
3 April: Luton (H)
6 April: Brighton (A)
9 April: Bayern Munich (H)
14 April: Aston Villa (H)
17 April: Bayern Munich (A)
20 April: Wolves (A)
23 April: Chelsea (H)
28 April: Tottenham (A)