The PDP's long list of aspirants contesting for the party's presidential ticket includes Senate President, Bukola Saraki; former vice president, Atiku Abubakar; Sokoto State governor, Aminu Tambuwal; Gombe State Governor, Ibrahim Dankwambo; and former governors including Sule Lamido, Ahmed Makarfi, Attahiru Bafarawa, Jonah Jang and Rabiu Kwankwaso.
The Fulani businessman and politician beat 11 other contestants to pave the way to face his kinsman Buhari, who also got the nod of the ruling All Progressives Congress (APC) earlier on Sunday.
Speaking on behalf of the other aspirants, Mr Saraki, at the venue of the convention, pledged to support Mr Abubakar.
"All the doubting Thomases that thought we would all walk out after the results have been announced, we are not going anywhere but walking with Atiku to victory".
The Governor also stated that no single person can influence the outcome of the national convention.
"Exactly 10 months after that pledge, I can, with gratitude to God and utmost humility, report to you that the PDP of today is improved, enhanced and has migrated from an opposition party to a ruling party in waiting".
Petrol, diesel prices cut by Rs 2.50 per litre
It has consistently resisted demands for excise duty cuts since May when pump prices first started to move up. In Kolkata, the petrol price was Rs 83.35 per litre while that of diesel was Rs 74.80 this morning.
"We have witnessed the most credible, transparent and fair primaries", the candidate said, adding that it is the most innovative process since the inception of PDP 1998.
The national chairman also promised Nigerians an all-inclusive government if the party's candidate is elected as president.
"Indeed the victor of this convention is the party which ensured that the elections went free, fair and credible that all aspirants accepted the result and willing to support the victor in the general elections", the party said.
He said "I have a right to vote as a delegate".
The Minister of Finance, Mrs Zainab Ahmed, says President Muhammadu Buhari has performed well and deserves to be re-elected in 2019.