The winner of the presidential elections was determined in one round according to the first-past-the-post system. Initial results from the election gave Sata the lead, but further results put Mwanawasa in first place and pushed Sata into third place. Interim results released after votes from 120 of 150 constituencies were counted put Mwanawasa on just over 42% of the vote; Hakainda Hichilema had 28%; and Michael Sata had slipped to 27%. When opposition supporters heard that Sata had slipped from first to third place, riots erupted in Lusaka. According to interim results Mwanawasa still held an easy lead in constituencies counted up to 16:00 on 1 October.