Chelsea’s title success gave them their fifth major crown in the club’s history and their second in 11 days.
Hayes’ side – who reached the Champions league semi-finals this term – had never won a trophy prior to her arrival in 2012, but this is the second double of her tenure, matching their efforts from 2015.
The Blues also won 2017’s transitional WSL 1 Spring Series, but were not awarded the WSL trophy because of the event’s one-off eight-game format.
They had looked set for a close battle with 2016 WSL champions Manchester City, but three defeats in their past five games left Nick Cushing’s side out of contention.
Chelsea will have to replace a number of key figures when they attempt to retain their title in 2018-19, with England midfielder Katie Chapman, 35, retiring and defender Claire Rafferty, 29, leaving at the end of the season.
But their immediate thoughts will turn to their final game of the season against Liverpool as they aim to finish a remarkable season unbeaten in the league.
Chelsea midfielder Gemma Davison:
“We knew that we’d have to stay focused on this game and we wanted to make sure we got the result as well to keep winning and stay unbeaten.
“We stayed focused and patient throughout the game. Good teams do that, and we put the pressure on in the last 30 minutes and got our rewards.
“We all know that every player in our changing room can make a difference. Drew Spence has had a phenomenal season and she deserves a lot of credit for that goal.
“This whole squad’s got a good character about it and we’ve displayed it all season.”