The Pakistan Army had issued clear instructions to police and local government officials across the country to not interfere in February 18 polls, a media report said in Islamabad on Friday.
The local administrations, especially the nazims or mayors, were told by the "relevant centres of power" that the polls had to be "very free and fair" and "no nonsense was to be tolerated", a key decision which turned the balloting into a free and fair exercise, it said.
The instructions issued by the military authorities were a follow-up to the announcement made by the army before the election that it would not be responsible for the quality of polls.
However, the army had said that it would only respond to calls from the civil administration to deal with law and order problems.
The army's move was a "key factor that changed the scenario within 36 hours," The News reported.
An opposition candidate who won by a huge margin said district police chiefs, nazims and all Election Commission officials had received the instructions from the army and "it was visible why the polling and the results were so transparent."
"I was surprised when I complained of some problems at a couple of polling stations and before anyone else, the police were already there to sort out the matter," said the candidate, who fought the polls from a closely-contested seat in Punjab province.
The position taken by the army was the outcome of a decision by its chief Gen Ashfaq Parvez Kiyani, who had said before polls that the force would not be involved in the elections, which were a responsibility of the Election Commission and the government, the report said.
Insiders in Islamabad said a "script" for rigging the elections was ready and the Pakistan Muslim League-Q, which backs President Pervez Musharraf, and top people in the presidency believed it would be "executed, in letter and spirit, on election day."
"But the Army's decision to pull back and declare itself a non-party in the quality of the elections was a major factor, followed by clear instructions to all Inter Services Intelligence, Military Intelligence and local administration officials under the administrative control of the army, which made the difference on the election day," a newly elected PML-N member said.
The member also said the same policy will be followed by the Pakistan Army with regard to the formation of a new government.
"The army will stay neutral and the presidency will have to fight its own battles with political supporters, if they have any," he added.