Manchester City finished second with a 3-1 win at fourth-placed Liverpool.

Unbeaten Arsenal were 5-0 winners at Bristol City to go third and Reading drew 1-1 at Sunderland to finish sixth.

Starting the final day top of the table, level on points with Man City but with a vastly superior goal difference, Chelsea controlled their own destiny with an assured performance at Birmingham.

After Kirby was clattered in the box by Birmingham keeper Ann-Katrin Berger, Carney fired in from the spot against her old club to make it 1-0 and, after the break, Berger then spilled Gemma Davison’s cross towards Kirby, who easily tucked in the second.

Chelsea’s win ended Manchester City’s run of three consecutive domestic club trophies, as Emma Hayes’ side added to their double-winning year of 2015.

The Spring Series was a one-off, transitional competition aimed to bridge the gap between the old summer WSL campaigns and the first winter season in 2017-18.

Teams played each other just once. Chelsea were beaten at 2016 champions Manchester City but clinched the title with three straight wins at the end of the campaign.

Hayes’ side conceded just three times in the series and scored 32 goals – 10 more than anyone else.

FA Cup winners and Champions League semi-finalists Man City finished their busy season with goals from Jill Scott, Mel Lawley and Megan Campbell at Liverpool, who netted a late consolation through Scotland’s Caroline Weir.

Arsenal – who finished just one point behind the top two – were dominant at eighth-placed Bristol City, with Louise Quinn, Jordan Nobbs, Chloe Kelly, Danielle van de Donk and Beth Mead all scoring.

At Sunderland, Melissa Fletcher had put Reading deservedly ahead, before Beverly Leon equalised for the hosts, who finished fifth in the table despite reverting to part-time status before the start of the season.