The results announced by the Independent National Electoral Commission, CENI, so far account for nearly 1.9 million ballots, out of a total of around 44 million registered voters in the vast central African country, the size of continental Western Europe and with a population of more than 100 million.
CENI said 60-year-old Tshisekedi, in power since 2019 and seeking a second five-year term, was leading with more than 81% of the vote.
The business magnate and former Katanga provincial governor Moise Katumbi, 58, follows with just over 15% of the vote and ex-oil executive Martin Fayulu, 67, at just over 1%.
The other nearly 20 opponents, including 68-year-old Nobel Peace Prize laureate Denis Mukwege, failed to gather 1%.
CENI has not established turnout rates of the December 20 and 21 polls but has still been gradually releasing the results since Friday, which include legislative, provincial and local elections.
The polls were supposed to open only Wednesday but were extended due to a range of logistical problems.
Opposition candidates denounced the "chaos" and "irregularities" that they claimed marred the vote.
Some are planning demonstrations for next Wednesday, while others are calling for the election to be annulled.
The Catholic Archbishop of Kinshasa, Cardinal Fridolin Ambongo, called the elections a "gigantic disorder" during his Christmas mass Sunday evening.
Like more than a dozen embassies before him, the cardinal called for "caution and restraint," in the poor yet mineral-rich country with a long history of authoritarian rule and conflict.
AFP reports that in addition to opponents' suspicions of the electoral process, the campaign in the lead-up to the election, has been marred by the conflict-torn east, which has seen a spike in tensions over the past two years with the resurgence of the M23 rebels, allegedly supported by Rwanda. Kigali denies the allegations.