The Mark Bradford-helmed Black Jack, which took line honours in 2009 as Alfa Romeo, was one second ahead of LDV Comanche at the first mark and kept its slim lead as the boats rounded the Heads at the harbour entrance and headed south to Tasmania.
Wild Oats XI, seeking a ninth line honours title, was third, about a minute behind the leading pair, but managed to overhaul Comanche as they raced along the New South Wales coast.
The trio were within sight of each other about two hours after the race started at 1 p.m. (0300 GMT).
Thousands of boats provided the perfect viewing positions for spectators as the 73rd edition of the 630-nautical mile bluewater classic got underway.
Despite the light conditions there was high drama shortly after the start when the Mark Richards skippered Wild Oats tacked too closely to Jim Cooney's Comanche and they almost collided.
Race organisers had predicted steady north-east winds of up to 20 knots as the 102 yachts headed down the New South Wales coast with the breezes freshening to 25 knots as they approached Bass Strait between the mainland and Tasmania.
InfoTrack, which is the fourth super-maxi in the fleet, set the race record of one day, 13 hours, 31 minutes and 20 seconds when they took line honours last year as Perpetual Loyal.
Skippered by 2012 Olympic Laser class champion and 2013 America's Cup winner Tom Slingsby, InfoTrack was fifth overall about two hours after the start of the race.
Covering approximately 630 nautical miles (1,170 km) of the Tasman Sea and notoriously treacherous Bass Strait, the gruelling annual race is Australia's premier yachting event.
(Reporting by Greg Stutchbury in Wellington; Editing by Peter Rutherford)
