The widower of slain former leader Benazir Bhutto will succeed Pervez Musharraf as president of Pakistan after winning a landslide victory in Saturday's election.
Partial results announced by officials after separate votes in the federal and provincial assemblies showed that Asif Ali Zardari won an overwhelming majority of the votes.
Pro-Zardari lawmakers, some in tears, shouted "Long live Bhutto!" as the results came in. The couple's two jubilant but tearful daughters, one carrying a portrait of their late mother, smiled and hugged friends in the gallery.
But the day also brought a brutal reminder of the threats to the nuclear-armed nation's stability when a suicide car bomber killed at least 16 people and wounded dozens in the northwestern city of Peshawar.
The blast destroyed a police checkpoint, collapsed several shops nearby and left a one-metre in the road. Civilians dug frantically with their hands in hopes of finding survivors.
Already head of the main ruling party, Zardari becomes one of the most powerful civilian leaders in Pakistan's turbulent 61-year history. Last month, he marshalled a coalition that forced longtime US ally Musharraf to quit as head of state.
Zardari, a novice leader stained by past corruption allegations, takes over at a critical time for the volatile, nuclear-armed Muslim nation of more than 160 million.
Pakistan's economy is crumbling and the attack was the latest in a string of suicide bombings usually claimed by Islamic militants who have steadily gained strength since Pakistan joined the US war on terrorism in 2001.
Washington is pressing Pakistan hard to eradicate Taliban and al-Qaeda havens near its border with Afghanistan. An American-led ground attack said to have killed at least 15 in Pakistani territory on Wednesday sparked outrage and embarrassed Zardari's party.
As expected, Zardari trounced Mushahid Hussain, a senator from the pro-Musharraf party routed in February parliamentary elections, and Saeed-uz-Zaman Siddiqui, a former judge nominated by the opposition party of another ex-prime minister, Nawaz Sharif.