A switch to a one-design boat, which all teams must use, is producing the closest race in the 41-year history of offshore racing's most prestigious race.
Yet none of the legs completed so far since the fleet left Alicante, Spain, on Oct. 11 has been as closely contested as the latest between Sanya, on the southernmost tip of China, and Auckland, New Zealand.
The Dutch team, Brunel, the second leg winners, retained a narrow 9.7-nautical mile (nm) lead over the overall race leaders, China's Dongfeng Race Team.
With just under 2,000nm - or about a week's racing - left in the 5,264nm leg, the rest of the six-strong fleet was no further than 25nm adrift in a remarkably close race.
Dongfeng's surge to within passing distance of long-time leg leaders Brunel represents an extraordinary comeback after a broken mast track, which keeps the mainsail attached to the mast, threatened to completely derail their hopes in the stage.
They fixed it while still sailing. Frenchman Kevin Escoffier was hoisted up the 33-metre mast with a resin gun and tool box to affect the repair.
Just two days ago, Dongfeng trailed Brunel by some 100nm at the back of the fleet and skipper Charles Caudrelier reported morale to be at rock bottom then.
Abu Dhabi Ocean Racing was lying third, but less than 1.5nm behind Dongfeng, even though they had been sailing effectively with one man down after Justin Slattery was stricken by flu early in the leg.