Millions of Burmese took to the polls Sunday in an election billed as the country's freest vote in a quarter-century.
Victory for Suu Kyi's party, the National League for Democracy, would weaken the power of the military-linked party, which is led by President Thien Sein, a former general.
In Yangon, the country's largest city, people lined up at polling stations before sunrise.
The long wait was a cause for concern for Aung Kyaw San, an election observer for the National Youth Congress, a civil society group.
"It isn't right for someone to have to wait more than one hour in line to vote," he said.
Hlaing Myint, a sales manager, waited for five hours, but said it was worth it.
"This is the only way to change things," he said. He said the new government's focus should be on improving education, health care and economic growth.
"And we need law and order," he added.
Opposition leader and Nobel laureate Suu Kyi also cast her vote Sunday.
Just before the polls closed, voters dashed in under pouring rain to cast last-minute ballots as election officials used a megaphone to announce time was running out.
At a monastery that served as a polling station, voters, journalists and election workers were barefoot as part of Buddhist tradition. As soon as polls closed at 4 p.m. local time, a padlock clicked shut at the gate.
Zaw Win, a retired supervisor of engineers, lined up at daybreak for his chance to vote. Now 67, he was a high school student when he experienced his first military coup. He tells CNN he's been through "so many kinds of government."
But he is optimistic that this time, his vote will matter.
"Now I vote for the party and for the person I like, he said. "So I am quite happy."
As he showed off his ink-stained finger -- a mark election organizers are using to prevent people from voting more than once -- he said the process was reassuringly straightforward.
"Before, I was worried about the election. But it was very easy."
Many people appeared to be coming to vote as families.
Su Hnin Kyu, 20, came to vote with her parents and two older brothers, and the family reveled in the holiday-like atmosphere. Her brother, Thet Naing, 23, said he was voting for the first time.
The family enthusiastically supported Aung San Suu Kyi.
Thet Naing said he would be happy if Suu Kyi's NLD wins the election, but also expressed concern about the possibility of rigging.
"If it's not clean we will be sad," he said.
Blogger, anti-hate speech campaigner and NLD candidate Nay Phone Latt, however, was maintaining a degree of skepticism. He told CNN that the party had monitored some irregularities, and had noted minor incidents of violence and attempted voter fraud.
He added that it is the rural areas where the opportunities for foul play would be most evident.
"I am not so worried for the downtown area (of Yangon)," he said.
"But I'm not so sure for the remote area. All of the media and all of the observers everybody should focus on some of the place in the remote area."
Sense of belief
Pro-democracy supporters are optimistic the election could be the beginning of real change in the country, which has been isolated for decades due to its repressive military-dominated government.
While the administration of current President Thein Sein has relaxed restrictions, pushing through expansive political and economic reforms and bringing the country out of decades of authoritarian rule and international isolation, watchers say that the elections are still far from free and fair.
Not least is the bloc of seats in the Hluttaw, Myanmar's parliament, which is earmarked for the military. A full quarter of seats are guaranteed for unelected military representatives. These members also have an effective veto over any proposed constitutional change.
Within U.S. government circles, there was some skepticism toward the vote.
"This is not going to be a high-quality election," a senior U.S. government official told CNN, speaking on condition of anonymity.
"The process is going to be fraught ... it is slanted toward the ruling elite."
Military mood subdued
The mood was less festive at a military hospital in Yangon that serves as a polling station for around 1,200 military doctors, nurses and relatives of hospital staff.
A plainclothes man identifying himself as an officer in the special branch security intelligence arm of the police accompanied CNN during its tour of the polling station.
When CNN approached voters to ask about the election, the unnamed officer shook his head at them. The voters then declined to be interviewed.
An official from the Union Election Commission, the body that oversees the vote, insisted that this election was much better than parliamentary elections in 2010, which were boycotted by the National League for Democracy.
"There are more people this time compared to 2010," said Daw Thein Thein Tun, the election official at the facility.
"There is more regulation, and this time there is more openness and transparency," she added. "You see the voting is free and fair."
Barred from presidency
Suu Kyi -- a national hero who spent nearly 15 years under house arrest -- is overwhelmingly her country's most popular politician.
Under the country's military-drafted constitution, she is barred from the presidency due to a rule prohibiting anyone with foreign family members from assuming top office. Suu Kyi's late husband was British, and her two sons have British passports.
The president is not directly elected by the public, but chosen by MPs following the vote. Suu Kyi will stand as an MP, and has hinted at a civilian candidate to put forward for the role.
Suu Kyi says she'd be "above the president" if her party wins Sunday's general elections. She made the comments during a news conference in Yangon on Thursday, and added that there have been irregularities in advance voting, fraud and intimidation -- and that the process was falling short of its billing as Myanmar's first free and fair election in 25 years.