The Olympic 86kg gold medallist from Rio 2016 and four-time world champion, aka the Russian Tank, won yet another title as Aliaksandr Hushtyn pulled out of a repeat of their European final from last year due to injury.
Sadulaev won that contest in Bucharest and their semi-final at last year's European Games in Minsk.
It completed a dominant couple of days for the Russian men who won eight out of the 10 freestyle golds on offer.
Friday's other highlight came in the 65kg final when Vazgen Tevanyan of Armenia scored a stunning win over Hungary's 2019 world bronze medallist Iszmail Muszukajev.
With 52 seconds to go and the scores tied at 1-1, Tevanyan completed a takedown and then followed it with no fewer than three consecutive gut wrenches to win 9-1.
Chamizo falls in the dying seconds
Olympic 65kg champion Frank Chamizo took silver in the 74kg class on Thursday, going down to 2019 U23 world champion Razambek Zhamalov.
Chamizo looked in ominously good form as he outclassed Azamat Nurykau of Belarus in the semi-finals, going 10-0 up with 2:02 remaining to win by technical superiority.
Zhamalov scored first in the final as Chamizo was penalised for passivity near the end of the first half.
The Italian hit back with a takedown on the counter to go into a 2-1 lead.
He looked set for victory but Zhamalov had the last say inside the final five seconds, pulling his opponent over by the chest to make the winning takedown with Chamizo's unsuccessful challenge making it a 4-2 decision.
Wiebe with work to do
In a field missing Japanese and American wrestlers, the women's wrestling standbout was Rio 2016 75kg gold medallist Erica Wiebe.
But the Canadian went down to Turkey's 2017 world champion Yasemin Adar in the 76kg semi-finals by fall.
Adar scored a takedown to go into a 2-1 lead and then was adjudged to have pinned Wiebe after a challenge by the Turkish team and heated discussion between the officials.
Wiebe then lost her bronze medal bout with two-time reigning European Games champion Vasilisa Marzaliuk, the Belarusian countering to score with a takedown inside the last five seconds.
Aline Rotter-Focken secured gold with victory by fall in the final, using her strength to pin Adar with 2:34 remaining.
The 29-year-old German was world champion at 69kg back in 2014 and claimed bronze at last year's Worlds at her new weight class.
Russia also won the women's team event with seven medals including two golds courtesy of Ekaterina Poleschuk (50kg) and Svetlana Lipatova (59kg).