Nigeria's election winner Muhammadu Buhari Buhari praises Goodluck Jonathan for peaceful handover

Nigerian election winner Muhammadu Buhari congratulated outgoing president Goodluck Jonathan for peacefully relinquishing power on Wednesday, a day after becoming the first Nigerian politician to unseat a sitting leader at the ballot box.

"President Jonathan was a worthy opponent and I extend the hand of fellowship to him," Buhari told journalists and supporters to loud applause.

"We have proven to the world that we are people who have embraced democracy. We have put one-party state behind us."

The margin of victory - Buhari got 15.4 million votes to Jonathan's 13.3 million - was enough to prevent any legal challenge.

In an unprecedented step, Jonathan called Buhari to concede defeat and issued a statement urging his supporters to accept the result, a signal of deepening democracy in Africa's most populous nation that few had expected.

The rules state he must officially hand over on May 29.

His rival All Progressives Congress Party (APC) wasted no time in crowning him a "hero" for his good sportsmanship.

Jonathan's People's Democratic Party (PDP) has been in charge since the end of army rule in 1999 but had been losing support due to several oil sector corruption scandals and killings by Islamist militants in the northeast.

"You voted for change and now change has come," Buhari said.