Blues' fans have been desperate to see the Matildas' captain back in the line-up after her long injury lay-off, especially after they'd proved toothless in midweek when City handed them their first defeat all season in the Women's Champions League quarter-final first leg.
But on Friday, Chelsea boss Sonia Bompastor ruled out any prospect of Kerr returning to competitive action for them until at least after the forthcoming international break, meaning a mid-April return at the earliest.
So Sunday's come-from-behind win at City's Etihad Stadium felt like a huge one for Chelsea, with the champions reasserting their dominance and surging eight points clear at the top as Erin Cuthbert popped up for the winner in stoppage-time.
The win came eight days after Chelsea had beaten City in the League Cup final and will now give them more confidence that they can overturn a 2-0 deficit when the teams meet for the final match in their 'tetralogy' in the Champions League second leg on Thursday at Stamford Bridge.
But City, under interim boss Nick Cushing, should be stronger on Thursday as Mary Fowler, who only got half-an-hour off the bench on Sunday amid the team's recent hectic schedule, seems sure to return to the starting XI.
When Brazilian Kerolin put City ahead midway through the first half, alarm bells were ringing for Chelsea, but they grabbed an equaliser through Aggie Beever-Jones' four minutes after halftime, before Fowler's introduction just before the hour.
Outstanding in midweek, Fowler went on to have a quiet afternoon and Chelsea deserved their late triumph after Rytting Kaneryd and Lauren James had both come close before Cuthbert's brilliant diving header from Ashley Lawrence's cross sealed victory in the 91st minute.
Elsewhere, in a London derby featuring three Matildas, captain Katrina Gorry was West Ham's driving force as she led them to a 2-0 win over a Tottenham side featuring Charli Grant and substitute Hayley Raso.
Josefine Rybrink scored a 17th-minute own goal before Viviane Asseyi struck with an free-kick in stoppage time.
Leicester beat Dario Vidosic's Brighton 3-2, a blow for the Seagulls in their bid to finish fifth in the WSL behind the league's 'big four', while Manchester United ran out 4-0 winners at Aston Villa to move seven points clear of neighbours City in third place. Â
