Khan, who aspires to be the country's next prime minister, said in a televised address to the nation on Thursday that "thanks to God, we won and we were successful."
He added: "If God wills, we will set an example."
Pakistan's election commission has not yet released official, final results but Khan has maintained a commanding lead according to projections by many television stations, though it's unclear if he will have to form a collation government.
Khan's message of a "new" Pakistan resonated with young voters in a country where 64 per cent of its 200 million people are below the age of 30, according to a United Nations report.
More than a dozen TV channels in Pakistan, based on official but partial counts, are projecting — using their own, undisclosed methodologies — that Khan's Pakistan Tehreek-e-Insaf party is getting as many as 119 seats of the 270 National Assembly seats that were contested.