DAKAR, Senegal — President Macky Sall of Senegal looked set to win a second term in office, according to preliminary election results announced on Thursday, a victory that would come as no surprise after the leader used his power to make sure he faced little competition.

In a strong performance, Mr. Sall appeared to have taken 58 percent of the vote, the West African nation’s electoral commission announced, five days after votes were cast on Sunday.

The election runner-up, Idrissa Seck, joined three other opposition candidates in a joint statement that said they would not appeal the election results.

“We strongly and unreservedly reject this result,” the statement said. “We will not make any appeal to the Constitutional Council. It is clear that the incumbent has confiscated the will of the sovereign people and will be alone in assuming the consequences in front of the people and in the face of history.”