Appeals Court sitting in Nairobi on Friday nullified Embakasi South MP Julius Mawathe's victory after protracted battle in court.
In March this year, Justice Grace Nzioka dismissed a petition filed by former MP Irshad Sumra on grounds that the election was free, fair and verifiable.
But through lawyer Edwin Sifuna, Sumra moved to appeals court where he challenged the initial court decision.
"I was very sure that we won in Embakasi South. The appeals court has now confirmed our victory. We are ready to move to the ballot," he said.
ODM Secretary General Edwin Sifuna added: "The ODM party is the most popular party in Nairobi. We thank the court for giving us another opportunity."
While Mawathe was elected on a Wiper ticket, Sumra was defending his seat on ODM party. The two parties form the NASA coalition.
In his petition, Sumra argued that the August 8th polls were marred with violence, improper influence and intimidation.
During the August polls, Mawathe was declared winner having scored 33,880 votes to Sumra's 33,708 votes.
Should Mawathe fail to appeal at the Supreme Court, another epic battle between Kalonzo Musyoka and Raila Could could be ignited in Nairobi.
Of the 17 parliamentary seats in Nairobi, Jubilee bagged 9, ODM 7 and Wiper managed the Embakasi South seat only.