But we can't stop here. We've got another chance in just a few weeks time to pull off another victory like this one, in the Herne Hill by-election in Lambeth, and we need your help.
Last time around we lost out by 504 votes on electing a councillor in the ward, and it's been Green-held in the past, so we know we can win. Conversations on the doorsteps, alongside the St Ann's result today, show that Labour voters are coming to us in droves - but only if we speak to them.
We're hearing that voters feel let down by Labour - we know Greens will stand up for our communities.
We're hearing that housing, parks and local services all need massive improvements - we know Greens will work hard to get things fixed.
And more and more we're hearing that people want Green representatives that can make the change they need, when they hear our pitch.
We need to have hundreds more conversations between now and polling day. Can you help?