Lawyers for the Movement for Democratic Change party have arrived at court less than an hour before closing time to submit papers alleging the July 30 vote was rigged.
The Zimbabwe Electoral Commission has said President Emmerson Mnangagwa and the ruling Zanu-PF party won the election.
Mnangagwa, an ex-vice president and long-time confidant of former leader Mugabe, says he wants to make Zimbabwe more open and democratic.
However, soldiers opened fire during opposition protests in Harare on August 1, with six people killed, and foreign governments and human rights activists have expressed concern about reports of opposition supporters being targeted by security forces since then.
--AP--