The Monaco-registered 100-footer crossed the River Derwent finish line under the cover of darkness at 1:37am (local time) on Wednesday.
Black Jack's time of two days 12 hours 37 minutes and 17 seconds was the slowest since Nicorette III's win in 2004.
Black Jack had been locked in a tight three-way tussle down Tasmania's east coast with runner-up LawConnect and third-placed SHK Scallywag 100.
LawConnect finished about two-and-a-half hours behind Black Jack after this year's fleet was decimated by rough seas with 36 of the 88-strong starting field forced to retire.
"It was tough in the beginning. The first 30 hours were pretty rugged," Black Jack skipper Mark Bradford said.
"We had a tough race with both the (supermaxis). We dropped Scallywag at the end for a bit but she came back and LawConnect was right there the whole way."
Bradford said he spent the first 20 hours below deck.
"I just had internal problems, mostly my stomach was coming out of my mouth," he said.
"Maybe it's in my DNA. I'll put it down to the conditions"
Black Jack previously claimed line honours in the 628 nautical mile bluewater classic in 2009 under the name Alfa Romeo.
It finished fifth in the most recent Sydney to Hobart in 2019 and was second to Wild Oats XI by 28 minutes in a 2018 thriller.
For the first time, owner Peter Harburg was not aboard a Black Jack yacht and instead greeted his team at Constitution Dock in Hobart.
"It is very emotional. It is the grand prize of yachting in Australia. For me it's the first time I've been involved in a winning team," he said.
"I don't know whether I want to cry or laugh or give Mark another hug. I can't describe it."
Celebrations were subdued, with crew members not allowed to disembark until they had a confirmed negative rapid antigen COVID-19 test result.
Black Jack missed a chance to compete against LawConnect and SHK Scallywag 100 in the inaugural Australian maxi championship earlier this month because a crew member tested positive for COVID-19.
Their programme had already suffered a setback when the boat's mast broke in the Brisbane-Gladstone race in April.
"We started with a 66-footer as Black Jack and we've worked up to this," Harburg said.
"We've won every race on the east coast of Australia and we've beaten every other yacht on the east coast of Australia at different times.
"But this is the prize that has eluded us all along."
Bradford said Black Jack only suffered minor breakages in a race whereas many smaller competitors were crippled by serious issues.
The last time a similar number of yachts retired was in 2015 when 25 failed to finish.
Owner and skipper of LawConnect, Christian Beck, said lighter winds following the rough period were "perfect" conditions for Black Jack.
"If the forecast had have been true, we should have won. But because it was really light on the second day it was very difficult to win," he said.
"Coming second in a heavy boat like this with a day of light air was a good result. I'm very happy with what the crew did."
Some 40 boats remain at sea, with Mayfair, Celestial and Ichi Ban among handicap frontrunners.
