In a game of few chances, Arsenal were once again able to lean on their set-pieces and Nicolas Jover’s famous playbook.
Not many clubs have a mural of their set-piece coach outside the ground but, given their value to Arsenal, it is no surprise there’s one of Jover just a stone’s throw away from Emirates Stadium.
So often when the Gunners have needed a breakthrough, set-pieces have come to their rescue and that was the case against Chelsea.
In a turgid game, where both teams suffered from playing without a recognised striker, Mikel Merino’s header from a corner was enough to secure Arsenal a 1-0 win.
It was a reminder of the value of set-piece goals for the Gunners and how they have missed them over the past few months.
Indeed, this was their first goal from a set-piece in 12 matches in all competitions. The last one was back in the middle of January against Tottenham.
The absence of Bukayo Saka, whose delivery is so deadly, has impacted the team - but so has opposition defences getting wise to Arsenal’s routines.
The one that beat Chelsea was a new one. Earlier this season, the Gunners’ tactic was to load the back post before rushing to the near one.
This time, they had a cluster of players at the near post and Merino attacked the ball from the edge of the area at pace. Reece James could not keep up with him and the Spaniard’s header looped over Robert Sanchez and into the bottom corner.
Set-pieces were crucial for Arsenal in the first half of the season. In the opening 21 games of the Premier League campaign, they scored 12 goals from them. The proceeding seven, however, yielded none.
Given Mikel Arteta’s side still have nine more league games - and the small matter of a Champions League quarter-final with Real Madrid to come - the need to use set-pieces will grow as they continue life without a recognised striker.
Merino, again, did a solid enough job, here. He was certainly more effective than Chelsea’s stand-in Pedro Neto, who spent the afternoon being bullied by Gabriel and William Saliba.
Since Merino was moved to the No9 role last month, he has four goals in seven games - which is, perhaps, better than many predicted.
The title race is over, however this victory at least cemented Arsenal’s position in second place in the league.
It was not the 5-0 thrashing the Gunners enjoyed against Chelsea almost a year ago today, but it was a case of job done and eased fears of being dragged into a fight over Champions League qualification.
Arsenal are now 12 points off leaders Liverpool, however more importantly the gap to sixth now stands at 11.
The Gunners can rest easy and full focus will be on toppling Real Madrid next month.