The count from Thursday's voting was a lengthy process because the second choices of voters who chose one of the five other candidates had to be factored in, and some paper ballots that were inadvertently put into storage without being counted had to be dug up, The Daily Telegraph reported.
Johnson's victory, while narrow, was one of the few for the Conservative Party in local elections. The Labor Party picked up about 800 local council seats.
Livingstone, nicknamed "Red Ken," said he is leaving politics. He predicted Johnson will be the next Conservative Party leader.
The election was a humiliation for the Liberal Democrats, allied with the Conservatives in government. The party's local representation is at its lowest point ever and it ran behind the Green Party in the London mayoral contest.
Some Conservatives suggested Prime Minister David Cameron should make a right turn, The Independent reported. Eleanor Laing, who represents Epping Forest north of London, said the prime minister should pay attention to "Conservative MPs who represent the real people of this country" and not to "Liberal Democratic intellectual urban elite with the student politics ideas of reforming the constitution and taking forward green policies."
Among smaller parties, the election was a disaster for the British National Party, which lost all six council seats it was defending. Lady Sayeeda Warsi, the Conservative co-chair, suggested that the Euro-skeptic United Kingdom Independence Party or Ukip, has replaced the BNP on the extremist right.
The local elections are usually seen as a test of how well parties will do in the next general election. But Conservative leaders pointed out that Labor, under Prime Minister Tony Blair was crushed in local elections in the late 1990s, only to smash the Conservatives in the 2001 general election.