With tensions simmering in the vast nation's volatile eastern provinces, the 60-year-old president known as "Fatshi" picked Kinshasa's 80,000-capacity Martyrs sports stadium for the ceremony.
The stands were packed well before midday with singing and dancing in full flow awaiting the arrival of what the authorities said would be some 20 invited heads of African states.
Tshisekedi is the son of the late historic opposition figure Etienne Tshisekedi.
He became president in 2019, promising to improve living conditions in the DRC — which boasts mineral riches but has a largely impoverished population of 100 million — and put an end to 25 years of bloodshed in the east.
He campaigned strongly on his first-term achievements such as free primary medication, asking for another mandate to "consolidate" the progress, but critics dispute his claims of success..
More than 40 million people were registered to vote on December 20 last year for a president, as well as national and regional lawmakers and municipal councilors.
'Gigantic, organized mess'
Polling was officially extended by a day to account for multiple logistical snarls and continued for days afterwards in remote areas.
In the end, Tshisekedi officially triumphed with 73.47 percent of the vote.
Moise Katumbi, a former governor of the central region of Katanga, came a distant second with 18.08 percent.
Martin Fayulu, who says he was also robbed at the last presidential vote, garnered five percent.
Nobel peace prize winner Dr. Denis Mukwege, who won the Nobel Peace Pprize winner for his work with rape victims, scored 0.22 percent.
These candidates called for the election results to be cancelled. A protest planned for December 27 was banned and snuffed out by the police.
The archbishop of Kinshasa denounced the elections as a "gigantic, organized mess."
Accusations of fraud and an "electoral hold-up" have not abated and the fear of violence remains real in a country with a dark political past.
Security challenges
Katumbi and Fayulu have appealed to supporters to "show their discontent" on Saturday, and urged people "to stand up and say 'no," from wherever they happen to be.
AFP reporters said tires were burnt Saturday morning on the streets of Goma, capital of the conflict-torn eastern province of North Kivu.
In the provincial town of Beni, also in the east, youths tried to set up barricades but police intervened.
The electoral commission, known as CENI has recognized cases of fraud, vandalism and intimidation, as well as the use of illegal voting machines, AFP reported.
In the general election, the vote has been annulled for 82 candidates — including three government ministers and four provincial governors.
The security challenge remains monumental for Tshisekedi.
There was a lull in fighting in the east during the elections but violence has since resumed between the army and M23 rebels, allegedly backed by neighboring Rwanda, though the government has distanced itself from the rebel group..
Since mid-December troops from the 10-nation Southern African Development Community, SADC, have been discreetly arriving in the DRC.
They are taking over from an East African peacekeeping force whose mandate was ended by the DRC government, which alleged it colluded with the rebels instead of fighting them.
A senior army officer said on Tuesday that Kinshasa was counting on them to help re-capture ground from the M23 militia, which has conquered swathes of territory in the east since taking up arms again in 2021.
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