Wednesday's fixture at the Emirates was the final home game of the season for Arsenal; it was also their final game in hand, having dealt with UEFA Women's Champions League fixtures, as well as the inaugural FIFA Champions Cup.
The Gunners had been quick starters at home over the past few months, but a couple of shots from Beth Mead and Alessia Russo were all there was to show in the opening 15 minutes.
Mead was making her 249th and penultimate appearance for the club. She came inches away from breaking the deadlock with a header, provided to her via a pinpoint cross from Emily Fox. Courtney Brosnan in the Everton goal got a touch before the ball bounced off the underside of the bar and on the line, rather than behind it.
Arsenal won the ball back in midfield, and Russo raced past the Everton backline to get a shot away, which trickled through the legs of Brosnan, but was cleared away before it could be tapped home.
Renée Slegers' side started to increase the tempo as the first half developed, but were still waiting for that crucial opening goal.
Everton did not have many opportunities in the first half, but were almost gifted the opening goal when Lotte Wubben-Moy played a loose pass, which was picked up by Clare Wheeler, the winger spotting Anneke Borbe off her line, but the chip had too much lift on it, and grazed the top of the net.
Mead came close again, striking the bar this time. In a first half with few chances, the England winger had come closest.
Laia Codina fired home from close range early in the second half, but she was flagged for offside.
Everton had defended well, and it was going to take a piece of individual quality to break them down - Olivia Smith almost provided that moment when she cut inside and smashed an effort which looked to be flying into the top corner, only for it to crash off the bar once more.
Smith created some space down the left once more and pulled the ball back to Russo, who could only toepoke an effort into the gloves of Brosnan.
For the Toffees, considering they had conceded 10 goals in their five previous WSL games, they had been a lot more solid defensively tonight.
A combination of Arsenal substitutes almost helped to find the lead with ten minutes to play, but Caitlin Foord's cross was headed over by Stina Blackstenius.
Everton had been defending deep for the large part of the second half, but Ornella Vignola nearly gave the away side a famous win at the Emirates, the Spaniard's shot from the edge of the box taking a big deflection which left Borbe rooted to the spot, but crucially bounced just wide of the corner.
Blackstenius won it in the 93rd minute for Arsenal. A scramble from a corner saw the ball land at the Swede's feet on the penalty spot, and she tapped home into a virtually empty net.
It was a massive goal for the Gunners, moving them two points behind Chelsea in third, meaning that only a point would be required away at Liverpool on Saturday to secure a spot in the League Phase of the 26/27 Women's Champions League.