The fixture had previously been earmarked as a potential title decider, but the Gunners had already mathematically secured top spot and so it became more a case of playing for pride.
Both teams went close to scoring over the course of the game, but Arsenal substitute Emma Mitchell netted the only goal of the game with a stunning late effort from distance.
Not only did it secure the new champions a win, it also ensured all the focus was on them as it denied the previously unbeaten Manchester City bragging rights over an 'Invincible' season.
Elsewhere, Birmingham fell just short of catching third place Chelsea, despite a strong run of four consecutive wins to finish the campaign. It was, however, a record points tally.
The Blues beat relegated Yeovil 2-0 after a quick fire second half brace from Charlie Wellings, but it wasn't enough as Chelsea edged a five-goal thriller against Reading. Bethany England scored the decisive Chelsea goal after Ji So-yun had broken the deadlock and three goals in three minutes from Tash Harding, Karen Carney and Fara Williams early had tied it at 2-2.
For Swedish goalkeeper Hedvig Lindahl, it was a final game for Chelsea.
Yeovil's loss against Birmingham unfortunately ensured that they finished the season on negative points after succumbing to administration and receiving a 10-point deduction in March.
Perhaps suffering from an FA Cup final hangover after being defeated at Wembley by Manchester City last weekend, West Ham slumped to a 4-0 home loss against Brighton.
Kayleigh Green, Megan Connolly, Amanda Nilden and Ellie Brazil scored the goals for the Seagulls, with the game also representing the professional retirement of West Ham pair Lucienne Reichardt, 28, and Claire Rafferty, 30 - the latter was an unused substitute.
Final bragging rights of the season went to Liverpool after beating Everton in a Merseyside derby. After Courtney Sweetman-Kirk headed the opener for the Reds, what proved to be the winner was scored by Niamh Charles in the first half. Everton pulled one back through Abbey-Leigh Stringer, but Amy Rodgers eventually sealed the 3-1 victory two minutes from full time.
Liverpool, WSL champions in 2013 and 2014, finished the season eighth and will hope that the 2019/20 campaign offers a brighter outlook after a difficult 10 months.
Next season will mark the formal rebranding of the league to the 'Barclays FA Women's Super League' after a multi-year partnership was agreed with the bank earlier this season.