The victory marks a remarkable turnaround for the Tories but above all, a personal win for Mr Johnson and his special adviser, Dominic Cummings.
Despite the criticism gained in recent times, the former Vote Leave campaign director can arguably be credited for the Tory triumph.
The No.1 talking point of Mr Johnson and the Tories through the six-week election campaign was “Get Brexit done”.
Mr Johnson cited it repeatedly.
On Wednesday, he tweeted it more than 20 times and was back at it on Thursday morning.
Earlier in the week, he broke through a foam wall with a bulldozer emblazoned with the phrase.
As a result, when political focus groups were asked to shout out the first party slogan they remembered, people said: “Get Brexit done.”
The catchphrase resonated in the same way that "Take back control" did in the 2016 EU referendum.
Mr Cummings, a former aide to Michael Gove, effectively ran the Vote Leave campaign three years ago, by using data-driven campaigning to win over undecided voters, pushing a small number of key messages.
Drawing on his previous campaigns against the euro and a regional assembly for the north-east, Mr Cummings oversaw the group’s aggressive use of statistics and social media.
It was Mr Cummings who coined the catchphrase “Vote Leave, Take Back Control”.
The group’s initial legal name was "Vote Leave, Get Change" but Mr Cummings insisted on changing it as he had realised that "control" was a more seductive message.
One of his colleagues told the Financial Times in 2016: “He came to one meeting and said, ‘we’re going to push this’."
The same type of language was used by Mr Cummings during his earlier crusade against the single currency.
In 2003, he had claimed that adopting the euro would be like “giving away control of our economy”.
His slogan was swallowed almost entirely by Mr Johnson in 2016.
In a TV debate during the referendum campaign, the Tory grandee used the words “take control” no fewer than seven times in his one-minute opening statement.
Many people on social media are now congratulating Mr Cummings for winning at the polls, for the third time.
One user wrote: “Turns out Dominic Cummings is good at politics after all!””
Another one added: “The great hero of this evening is Dominic Cummings. Long may he continue.”
Sting Abell, editor of The Times Literary Supplement said: “Another point that has to be accepted is that Dominic Cummings is very good at winning elections.”
