Her victory was splashed across a digital signboard above the Rangoon HQ of her party, the National League for Democracy (NLD).
The building has been full of campaigners, journalists, election observers and supporters in the days leading up to Sunday's byelections.
If confirmed, Aung San Suu Kyi's win will mark the moment that both Burma and the rest of the world have awaited for decades.
Burma has been ruled by a military junta almost exclusively for the past 50 years and only recently lifted certain repressive laws.
According to unofficial figures, Aung San Suu Kyi was leading the polls against her rival, former military doctor U Soe Min of the government-backed Union Solidarity and Development party (USDP), with 65% of the vote in 82 of her constituency's 129 polling stations.
Despite being the face of democracy in her country, this will be the first time that Daw (Auntie) Suu, as she is known in Burma, will hold public office.
She is expected to spend half her time in the capital, Naypyidaw, and the other half in her constituency, Kawhmu, a smattering of 100-odd villages that begin just 20 miles southwest of Rangoon.
The election has been touted as the make-or-break moment in Burma's history and a crucial test of the reforms initiated by the president, Thein Sein, that many hope will put a final end to years of international sanctions.
Despite complaining of many irregularities in the lead-up to the vote – among them harassment against NLD candidates and deceased people said to be on electoral rolls – Aung San Suu Kyi told a recent news conference that she did "not at all regret" taking part in the elections and that they marked "a foundation stone for the future of democracy in Burma".
