Mobbed by the media, with fans wildly chanting his name, Britain's biggest political celebrity strode into Birmingham's New Street station.
It was a scene unlike any other in recent times, more befitting a rockstar than a Conservative mayor of London.
Crowds of media and commuters jostled to take snaps, and passers-by chanted "Boris, Boris, Boris" and "There's Only One Boris Johnson".
More photographers greeted him as he arrived at the Hyatt Hotel, with Boris telling reporters he was "here to support the party" rather than make trouble for the Prime Minister.
And he stood, rabbit in the headlights, in front of flashing cameras after getting into a lift whose doors were slow to close.
Johnson topped a national YouGov poll in mid-September, which found him to be the most respected politician in the country, more popular than Margaret Thatcher and David Cameron.
Boris Johnson is now 12/1 to be the next Prime Minister, according to Ladbrokes, beaten only by Ed Miliband and Yvette Cooper.
His address on Tuesday is expected to top Cameron's speech on Wednesday as the highlight at the Conservative Party conference, and he's holding an "Olympotastic" victory rally on Monday evening.
Earlier, he told BBC Radio 5 Live that it was "unverifiable" whether Cameron was a better prime minister than he would be.
And as for whether he like to be prime minister after he is done with being London mayor?
"After four years are up, heaven knows. I will be an old man."
Although he declares himself loyal to Cameron, he has often launched blistering attacks on the government, especially over transport and his pet cause, a new London airport on "Boris Island" - recently accusing the government of "continued inertia which is being fully exploited by our European rivals".
A poll conducted by the grassroots Conservative Home found that Boris was the overwhelming favourite to succeed Cameron, with 37% of Tory members backing the mayor to take over should the Tories lose the 2015 election.