The African Union on Friday congratulated anti-establishment opposition candidate Bassirou Diomaye Faye on his victory in Senegal's presidential election and hailed the "unanimous acceptance of the results".

In a statement, African Union Commission President Moussa Faki Mahamat said he "warmly congratulates" Faye on the official declaration of his first-round win, while wishing him "full success in his weighty and noble charge".

According to provisional results, Faye won the first round of the vote outright with 54.3 percent, far ahead of incumbent Macky Sall's hand-picked candidate, former prime minister Amadou Ba.

Senegal's Constitutional Court could declare Faye the official winner before the weekend, which would make a handover possible before April 2, the official end of Sall's term.

Faye, 44, was only freed from prison 10 days before the election, along with his mentor Ousmane Sonko, who was barred from running following a criminal conviction he says was politically motivated.