After years of war, displacement and broken promises from religious parties and the secular Awami National Party (ANP), voters on the frontline of the Taliban insurgency rewarded Khan's untested party with the highest number of seats.
For Pakistan Tehreek-e-Insaaf (PTI), which previously only held one seat, it was a staggering victory in Khyber Pakhtunkhwa (KPK) - one of the most troubled parts of the country - and hands Khan an almost poisoned chalice of responsibility.
Bitterly opposed to US drone strikes and Pakistani offensives against Taliban fighters blamed for killing thousands of people, victory in the northwest propels PTI from the lofty ideals of opposition to the comfortable realities of government.
Many analysts believe Khan will have a rude awakening and will realise very quickly that his policies of appeasement are naive, that it is not just "America's war" and that the Taliban are not people he can do business with.
"They will wake up to reality very quickly because the stance of the Taliban is such that it is absolutely not reconcilable with any government in KPK or in the federal capital," said Saifullah Khan Mahsud of the FATA Research Center.
The ANP, which governed KPK for the last five years, was all but wiped out at the polls, sent packing by an electorate fed up with corruption and their inability to bring peace to the war-racked province.
Khan, on the other hand, presented himself as a charismatic leader. He visited repeatedly, he talked and walked among the ordinary people. He promised peace and he denounced the US drone strikes. It proved a heady combination.
The Taliban, who denounce democracy as un-Islamic, killed more than 150 people during the election campaign, including 24 on polling day itself. Secular parties in the outgoing government suffered by far the heaviest losses.
In a telephone conversation with AFP, Taliban spokesman Ehsanullah Ehsan said the insurgents would first "wait till political parties form their government in centre and Khyber Pakhtunkhwa" before announcing their policy
But referring to PTI and the Pakistan Muslim League-N, which won the national polls, before the election he also warned that: "If they also come into conflict with Islam, then we will decide to target them."
That could present the PTI with the uncomfortable prospect of having to go back on the policies that got them elected, says Umair Javed, a Pakistani columnist.
"Right now Imran is very clear on ending things. That would mean you completely stop sharing intel, you put an end to the transit network for NATO, the (US) drone programme has to end.
"But being in power and having to govern a province is a huge experience for the party and will help in tempering some of their more extreme positions in the war on terror and relationship with the US," he says.
One crucial aspect will be the relationship between PTI in the province and Nawaz Sharif's government in the centre. Both leaders voiced similar positions on the war on terror though Sharif is seen as a pragmatist.
But even if a decision is taken to reach out to the Taliban to initiate a peace deal, similar policies of talks have unravelled in recent years.
"He wants peace without fighting the war. We could well see another peace deal, and after a few months of Taliban misrule and injustice public opinion would once more sour," said Shaukat Qadir, a retired brigadier and security analyst.
Pakistani troops have been fighting for years, but it was only in 2009 that the country largely united for the first time behind an operation against the Taliban in Swat after a video emerged in 2009 showing the flogging of a 17-year-old girl.
But much will likely depend on Pakistan's powerful military. Army chief, General Ashfaq Kayani, has been a strong US ally but junior ranks are increasingly fed up with the bloody war and opposed to American intervention.
"It is a very tricky situation because on the one hand the army chief mentioned recently that political forces and the military should be on the same page and there is no compromise with those forces which they are fighting," says retired general Talat Masood.