Former deputy leader Paul Nuttall and London Assembly member Peter Whittle won the loudest cheers from the Ukip faithful on Tuesday night (1 November).
The pair were joined on the Emmanuel Centre stage by former deputy chairman Suzanne Evans and John Rees-Evans, a hitherto unknown Ukip activist who once falsely claimed a "gay donkey" raped his horse.
The Westminster debate was the first of four leadership hustings — Newport, Leeds and Wolverhampton will host the 'People's Army' later this month— before Nigel Farage's successor is announced on 28 November.
The election was triggered after Diane James MEP dramatically resigned from the top job after just 18 days in the role.
Since then Ukip's former migration spokesman and leadership favourite Steven Woolfe quit the party following an "altercation" with Mike Hookem, the former soldier who denies punching his fellow MEP.
Ukip chairman Paul Oakden praised James over her "courageous" decision before kicking off proceedings.
Evans took to the podium first, winning applause for a pledge to "campaign loudly" against health tourism, while warning that Ukip had been "vulnerable" on the NHS issue in the past.
The former BBC journalist also attacked Jeremy Corbyn and Labour, branding them the "Islington set" and claiming the left-wingers praise the IRA.
Evans also said it was necessary to get "good 'Kippers" into teaching because children are apparently taught Shakespeare is a "global playwright" rather than a British institution.
Rees-Evans, meanwhile, warned Ukip was in "crisis". Billing himself as a "professional problem solver", Rees-Evans called for a "revolutionary change" within the party. He championed the idea of e-democracy so that every Ukip member could have a say on the party's policies and direction.
Nuttall, the front-runner in the race, said he had served his apprenticeship and claimed it was his duty to stand for the leadership. The Bootle-born politician also argued Ukip could become a "patriotic voice" for the working-class under his watch.
Read more: IBTimes UK interviews Suzanne Evans
"The future is bright, but to ensure it is Ukip must ignite," he declared. Nuttall later won loud cheers from Ukip members for urging the government to stop "any Saudi funding of mosques in this country".
Whittle, similarly, said Ukip must "fight the advance of Sharia law". When asked how he would promote Britishness, he said: "I would start very, very simply with one thing: every school has a Union Jack and a picture of The Queen."
All of the candidates went out of their way to praise Farage, who quit the party in the wake of EU referendum to "get my life back".
It later emerged that the Eurosceptic firebrand was around the corner from the hustings, getting his life back with the self-styled "bad boys of Brexit", Leave.EU founders Arron Banks and Richard Tice.
The group, including Belizean diplomat Andy Wigmore, even bumped into deputy Labour leader Tom Watson, who was also enjoying a drink at the Westminster Arms.
Ukip leadership timetable
- Submission deadline of midday (31 October)
- First hustings is held in London (1 November)
- Ballots sent to Ukip members (11 November)
- New leader announced (28 November)