Alicante - American-led Puma and Spain's Telefonica were locked in an Atlantic dog-fight through the dreaded Doldrums on Tuesday in the Volvo Ocean Race.
The pair had swapped the lead repeatedly in the previous 24 hours on the first leg from Alicante in Spain to Cape Town with Ken Read's Puma then narrowly holding the advantage over newly elected world sailor of the year, Iker Martinez.
The battle was testing both highly experienced skippers to the full in the Doldrums which is the area just north of the Equator where northern and southern weather systems converge leaving sailors with one of the biggest of all headaches - lack of wind.
In third place, Team New Zealand in Camper helmed by Chris Nicholson, were 269 km behind with France's Groupama 580 km adrift of the leaders.
Read, who skippered Puma to second place in the last race in 2008-09, told AFP: "It doesn't look like this Doldrums band (of little or no wind) is nearly as wide as last time. In the last race we parked for days.
"This time we might make it through unscathed. Tom Addis (Navigator) has done his homework and we think we've come up with a nice path."
The tussle between the top two is remarkably close since the pair have been sailing now for nine days covering some 3 700 km.
The race fleet of six was reduced by two after just 24 hours of the leg one start on November 5 in Alicante when Abu Dhabi Ocean Racing's Azzam and Team Sanya of China were both forced to retire from the opening stage after a first night storm in the Mediterranean.
Both boats will rejoin the race, contested over nine months, 72 000 km and widely regarded as the toughest event on sailing's calendar, for the second leg from South Africa to Abu Dhabi.
There are nine legs in all with the race finishing on July 8 in Galway, Ireland.
The four-strong fleet are still racing the first leg and are expected to arrive in Cape Town in just under two weeks.