In a highly unusual move, Farage, one of Britain's leading Brexit campaigners, did not turn up at the vote count in the southern English seaside resort of Clacton because, he said, the police had advised him there was a campaign to disrupt the result.
He also cancelled a victory speech planned for later on Friday.
"I am damned if I am going to stand on a stage, having won a resounding victory ... and be demeaned and humiliated by nobodies," Farage told supporters at a party before the result was announced on Friday.
He claimed he had won "fairly convincingly" and the result was an "overwhelming endorsement" of him.
The election was triggered after Farage resigned from parliament in July to seek a renewed mandate from voters in what he described as a war against an establishment bent on discrediting him with accusations about his finances.
The result, while a victory, underscored the political risks of Farage's gamble. With the resumption of a parliamentary investigation into his taking undeclared gifts from donors, the vote did little to remove a threat he wanted to sideline.
After Britain's main parties pulled out of the race, calling it a self-serving stunt, Farage's main challenger ended up being Count Binface, a figure created by comedian Jonathan Harvey, who has become a fixture of fun at British elections.
While Farage took 62.8 per cent of the vote, Count Binface, whose policies included capping the price of ice cream cones and conscripting anyone using a speakerphone on public transport, secured 26.7 per cent in a poll where turnout was 44 per cent.
Reform has seen its popularity wane after enjoying a lengthy lead in national opinion polls, driven partly by the funding accusations made against Farage, under investigation over whether he should have declared a Stg5 million ($A9.6 million) gift from a billionaire cryptocurrency investor.
A rise in support for the governing Labour Party has also weakened Farage's position: since Andy Burnham became prime minister in July, Labour has been enjoying a bounce in ratings, with the party leading Reform 28 per cent to 25 per cent.
Burnham appears to be consolidating a left-leaning bloc around Labour, while Reform is competing for a divided right-wing vote with the main opposition Conservative Party and the anti-immigration party Restore Britain gaining in support.
While Farage was always expected to win the election, his share of the vote was lower than forecast.
Shortly after the result was declared, the parliamentary standards investigation into his financial declarations - suspended after his resignation from parliament to fight the election - was listed once again as active.
At the heart of the investigation is whether he should have declared the gift from a Thailand-based billionaire before the 2024 national election.
Under parliamentary rules, members of parliament must declare any donations received in the year preceding an election within one month of taking office.
Farage has admitted receiving the money and not declaring it, but says he did nothing wrong.
If the parliamentary authorities conclude that Farage breached declaration rules, he could face suspension from parliament and another vote to retain his seat, when the main parties would most probably field candidates.
Speaking to Sky News, Count Binface referred to the possibility of a second by-election.
"You just said at the beginning of this interview that Nigel Farage is claiming victory, but in that case it's going to be a two-legged match like the Carabao Cup or the Cold War, because we're going to be back again in a few weeks, aren't we? We'll see what happens then," he said.
"Even if I got to 12 per cent, so one-in-eight people in Clacton would rather vote for a space warrior shaped like a bin than Nigel Farage."
with PA
