After spending nearly 60 years in office, BDP suffered a shocking setback at the hands of voters, who chose an opposition coalition and its presidential candidate, Duma Boko.
President Mokgweetsi Masisi, 54, of the Umbrella for Democratic Change (UDC), will take over after his Botswana Democratic Party (BDP) lost by a landslide for the first time in 58 years on Friday.
In an audio recording of a phone conversation with Boko, which the departing leader shared on social media, Masisi stated, "I will begin the process of handover tomorrow." This indicated a seamless transfer of power.
"I promise to always be there to offer you any advice you may require. We'll turn back to being a devoted opposition.
Terence Rannowane, the Chief Justice, formally proclaimed Boko the winner. It is with great honor and privilege that I announce his election as Botswana's president. He remarked on Friday, "I sincerely congratulate you for the confidence that the people have shown in you."
"The UDC has met the minimum requirement to be declared the next government," Osupile Maroba, a spokesman for the Independent Electoral Commission (IEC), told the AFP news agency earlier.
The first party to secure 31 of 61 seats in the assembly is deemed the victor under the nation's election system, and it has the authority to install its candidate as president and establish a government.
Botswana President and presidential candidate for Botswana Democratic Party (BDP) Mokgweetsi Masisi.
According to preliminary results broadcast on state television, the UDC exceeded the barrier and won 32 seats based on results from 55 of the 61 constituencies that were up for grabs. As a result, Boko, its leader, would be elected president.
Later on Friday, the IEC is anticipated to confirm the findings.
IEC tallies showed the BDP in fourth place, behind the party.
At a press conference in the capital, Gaborone, Masisi, who was running for a second five-year term in Wednesday's elections, stated, "We got it wrong big time in the eyes of the people."
"We had a strong belief in our message. However, by every metric, it is clear that I cannot pretend that we will establish a government.
The BDP was predicted to win and has been in power since 1966 in the diamond-rich country of Southern Africa.