The Conservatives no longer control of the three flagship London megalopolis as Labour has additionally fortified its clutch on the capital.
Despite the important victory in Wandsworth, Margaret Thatcher's "favourite council", Westminster and Barnet, earned by Sir Keir Starmer's party have been more moderate elsewhere in England.
The Tories had operated Westminster since its formation in 1964 and Wandsworth since it turned blue in 1978, not nearing not quite Mrs Thatcher's election as prime minister.
Sir Keir, talking from Barnet on Friday morning, said the outcomes are a "massive turning point for the Labour Party".
"From the depths in 2019 we are back on track now for the general election, showing what the change that we've done, the hard change that we've done in the last two years, what a difference it has made," he added.
Labour sources reported the wins in Wandsworth, known for its lower taxes, as "monumental".
"This was the Tories' jewel in the crown," one party source said. "Voters in Wandsworth have put their trust in the change Keir Starmer's Labour represents."
Shadow minister Rosena Allin-Khan and London Mayor Sadiq Khan commemorated together as the outcome came in.
Lib Dem leader Sir Ed Davey was smiling about his party's gains as he spoke to Sky News' Kay Burley, informing her people had used their mandate to communicate a word to Boris Johnson.
He maintained that Lib Dem gains were not protest votes against the government because "it's a real trend now" and said there is a "real chance" for the party, partly because the Tories are "failing so badly".
However, Conservative Party co-chair Oliver Dowden rebuffed Tory defeat saying the outcome were "more consistent with what you would expect in midterm in urban areas" - but admitted he was "disappointed" with those key losses in London.
"Labour is certainly not on the path to power and I believe Boris Johnson has the leadership skills, particularly the energy and dynamism to lead us into the next election," he added.
Triump in Barnet will also be perceived as a important achievements for Sir Keir and a possible sign of increasing confidence in the party's leadership.
The north London authority boasts of one of the UK's substantial Jewish populations, and as Labour was obstinately determined by allegations of antisemitism under erstwhile leader Jeremy Corbyn, the voting population in the area people for the party decreased.
A local Tory leader noted that the Labour triumph in Barnet "does not bode well" for the Conservatives for a general election.
Daniel Thomas said: "I think this is a warning shot from Conservative supporters and I think our loss today is not only due to the fact that I have just mentioned but also a fair number of Conservative voters who just didn't go out to vote, stayed at home".
Labour will be glad to have earned Southampton from the Tories, upturning the small majority Mr Johnson's party gained from the last set of local elections.
Sir Keir's party also acquired the new Cumberland authority, an important victory considering the fact that the area has three Conservative MPs in Carlisle, Copeland and Workington.
But the Liberal Democrats captured Kingston-upon-Hull in what will be perceived as a big loss for Labour.
Many of the so-called red wall councils are yet to be announced.
The Lib Dems also gained West Oxfordshire, where the Conservatives bowed out the majority they had grasped since 2000.
While Conservatives grasped Basildon, elsewhere in Essex, the Conservative leader of Colchester Council bowed out from his position to the Liberal Democrats.
Mr Johnson's party also bowed out in Peterborough, where the party desired to earn two seats, with the party now operating the council under minority control.
Voting has been taking place for councils in some parts of England, with more than 4,000 open to applicatiom as well as beyond the whole of Scotland and Wales, each with more than 1,000 position at stake.
The elections determines who will be answerable for handling local issues such as blue printing, habitation and garbage collections - but wider national issues such as the rise in the cost of living have also come to the forward.
Outcomes, coming in over the coming days could also prove key to the upcoming of the prime minister - and whether whispering of backbench discontent degenerate into a chorus of opposition inciting a no-confidence vote.
They will also throw more light on whether Sir Keir has been able to gain footing amid the squeeze facing the PM as an aftermath of partygate, the standard of living crisis and questions about the culture in Westminster.
In Northern Ireland, 90 assembly members are being cherry picked - with fears high as polls point to Sinn Fein overtaking the DUP as the wide extensive party, indicating Northern Ireland could have a nationalist pionner minister for the first time.
Mayoral elections have also been taking place - in South Yorkshire, Croydon, Hackney, Lewisham, Newham, Tower Hamlets and Watford.
In Bristol, people exercised their franchise to abolish the directly elected mayor system in the city in a referendum.
And in Scotland and Wales, computation does not begin until Friday, with the earliest outcomes not anticipated.until that afternoon.