"I know how to swing a bat," he shouted.
His next target, he boomed, would be the lion and tiger that his rival Nawaz Sharif used on his banners. "There's danger ahead for the circus cats."
First as a cricketer then as a politician, Khan, 60, has never wavered in self-belief. Weeks ago, his Movement for Justice Party was struggling with messy internal elections, its chances diminishing by the day.
Yet he never stopped talking of a grassroots revolution, a tidal wave that would sweep away a corrupt political elite.
Now, as he takes his electrifying roadshow up and down the country, analysts who had written him off are revising their predictions. He is still likely to fall well short of power but his anti-corruption drive has excited young voters, eager for Captain Khan to lead the country the same way he led his cricket team.
In his bullet-proof car, minutes after the rally, he admitted wearing body armour for the first time.
"I have on the insistence of my team. They think that because our graph is rising so rapidly the danger grows per day."
Khan said he had been told his name was on a list of the top five targets and as we head for the next rally our convoy is flanked by police cars. His former wife Jemima and two sons, who live in Britain, have told him of their anxiety but he remains one of the few leaders to address crowds without a bullet-proof screen.
The memory of Benazir Bhutto, assassinated in 2007 as she left a campaign rally, is never far away. "Benazir was not hit by the Taleban. Benazir was clearly killed by people worried she was going to come into power," he said.
This week, the party of President Asif Ali Zardari has begun hinting that Khan could be offered the prime minister's slot in a coalition. Sharif, whose PML-N party heads the polls, may also need Khan's seats - forecast at anywhere from 30 to 80. "How can you bring change by joining the status quo? There will be no deal," he said.
His most controversial stance is his approach to militancy.
He would order the US to stop its drone strikes and withdraw Pakistani troops from the border areas, ending what he sees as forces that drive young men to extremism.
Instead, he would rely on tribal leaders to negotiate peace.
"The way to do it is to take away their motivation, which is jihad. If people are willing to die for a cause it is very difficult to defeat them."
The position has earned him the nickname "Taleban Khan" and accusations that he is soft on extremism, but it is an approach increasingly articulated by other parties, tired of tens of thousands of deaths in a never-ending war.
After Attock his armoured car takes him on to two more rallies, each the same, with more than 10,000 people pumped up by pounding rock music.
He referred to a recent interview with Dickie Bird, the retired umpire, in the Daily Telegraph, in which he selected Khan as captain of his all-time world XI.
"We had nothing, no system, but somehow we produced world class cricketers out of that," shouted Khan before pausing, letting the crowd remember how he led his team to the Cricket World Cup in 1992.
The metaphor, of a country packed with resources but lacking leadership, is obvious to everyone before he makes his final point. His words are drowned out as if he had just hit a six.
