Comanche edged to victory in the Sydney to Hobart yacht race. (Photo: AFP)

Race favourite Comanche snatched victory in the gruelling Sydney-Hobart yacht race Saturday, edging InfoTrack in tricky conditions after a race that saw an ever-changing leaderboard.

The maxi's crew cheered and shook hands as they crossed the finish line at Hobart's Constitution Dock in 1 day, 18 hours, 30 minutes and 24 seconds.

More than 150 yachts sailed from Sydney into open ocean for the 75th edition of the annual race down Australia's east coast.

Comanche had led after a slow start in Sydney, but the French-designed and US-built yacht pulled wide of the pack early in the race.

That offered Hong Kong yacht Scallywag the lead temporarily, but Comanche's proved to be a wise decision as the field struggled in soft wind.

Comanche struggled for speed on the final stretch and its lead over InfoTrack narrowed to seven nautical miles toward the finish line.

That meant Comanche did not come close to its winning 2017 record of 1 day 9 hours 15 minutes 24 seconds over the 628-nautical-mile course. The yacht was also the 2018 runner up.

After weeks shrouded in bushfire smoke haze that forced the cancellation of the Big Boat Challenge, an event that foreshadows the Sydney-Hobart, the race began under clear blue summer skies Thursday.