New Delhi (CNN) -- Fresh from a landslide victory, Narendra Modi and his Bharatiya Janata Party celebrated in a parade, as supporters lined the streets in the capital, waving flags of the party and holding balloons.

Modi's party won 282 of 543 parliamentary seats, according to the country's election commission, bringing a clear majority and a resounding mandate to a single party to rule the world's largest democracy.

Modi, 63, is expected to officially be sworn in as India's new Prime Minister on May 21. He will have to shoulder great expectations, as voters flocked to his party on his pledge to reform the nation's slowed economy.

Prime Minister says goodbye

Meanwhile, outgoing Prime Minister Manmohan Singh submitted his resignation and made his last address to the nation, recalling his background from the subcontinent's bloody division into India and Pakistan in 1947.

"I owe everything to this country, this great land of ours where I, an underprivileged child of (the) partition, was empowered enough to rise and occupy high office. It is both a debt that I will never be able to repay and a decoration that I will always wear with pride," Singh said.

Singh, 82, leaves the office with a divided legacy. While his performance as finance minister in the 1990s has been praised for opening up India's economy, his recent years as Prime Minister were pockmarked by a spate of high-profile corruption scandals involving his Congress Party, as well as stalled reforms and a drop in growth.

"Friends, I am confident about the future of India. I firmly believe that the emergence of India as a major powerhouse of the evolving global economy is an idea whose time has come," Singh said in his TV address.

He concluded his speech by wishing Modi's government well and saying he prayed for "even greater successes for our nation."