Light-air specialist Black Jack shaded LDV Comanche by one second around the first turning mark and was first out of the Sydney Heads.
Wild Oats XI turned the mark in third, more than a minute behind the first two.
Wild Oats XI skipper Mark Richards earlier stressed the support of rivals Black Jack made the preparations of the eight-time line honours winner much easier.
"It could have been pretty difficult, the componentry is not easy to get, it's not off-the-shelf stuff," Richards said.
"It's just one of those things, but we got away with it with their fantastic help and we're very appreciative and it's worked out well for us."
Bradford was adamant all of the teams behind the four supermaxis - LDV Comanche, Wild Oats XI, Black Jack and InfoTrack - in the race would react the same way under those circumstances.
"What we did there was what anyone in this group does, because the assets are so hard to keep on the water," Bradford said. "It's not like you can just go down to Supercheap Auto and get some parts and sort the thing out. There's only four boats in this country that have the parts for those boats, so we would absolutely help our competition in that regard.
"We win a lot of races because we've got a big boat, but our whole thing is about competition, so we're really looking forward to this competition, we want them there.
"If it comes back to bite us and they beat us fair and square, it won't come down to the parts we gave them, it will come down to them sailing well."
Kiwi sailor Matt Mason is crewing on Wild Oats XI. The only fully Kiwi crew is on board Ran Tan II, skippered by owner Brian Petersen, and there are Kiwis on Hong Kong boat Beau Geste.
After trying to beat New Zealand sailors earlier this year in the America's Cup, Australian Jimmy Spithill has joined forces with another group of Kiwis on the LDV Comanche.
• A dream forecast yesterday had the four supermaxis on track for a potential race record, with 15- to 25-knot north-to-northeasterlies expected to continue.
"Having this forecast, an opportunity to try to get the record back is super important for the Wild Oats family," Wild Oats XI tactician Ian Murray said.
"In all my 24 times of going down there, it's never been as good as this. It's very rare that you get this sort of continual up the wind across the wind, wind start to finish sort of scenario, it's something we all dream about really."
The main stumbling block to eclipsing Perpetual LOYAL's 2016 race record of one day 13 hours 31 minutes and 20 seconds could be if the supermaxis become becalmed if they enter the Derwent River during a time when traditionally the wind shuts down.
"The numbers suggest the race record is easily achievable for I think any of the maxi boats," Murray said.
- AAP
