The New Zealand women's eight have caused a boilover at the rowing world championships, heading off the all-conquering United States in the heats.

The Kiwi crew held their form until the end of a tense race in Sarasota, Florida, pipping the three-time defending Olympic champions by less than a second.

With only the heat winners advancing automatically to the final on Monday morning (NZT), the New Zealanders were anxious to win and avoid a Friday repechage in the prevailing hot conditions.

Emma Dyke, Lucy Spoors, Rebecca Scown, Kelsi Walters, Kelsey Bevan, Georgia Perry, Ashlee Rowe, Ruby Tew and cox Sam Bosworth achieved it with a terrific front-running performance.


After jockeying for the early lead with Rio Olympic silver medallists Great Britain, the New Zealanders pulled clear just after the 500m mark and kept the US at bay for the rest of the journey.

Their time of 6 minutes 08.42 seconds was the second-quickest overall, with Romania fractionally faster in the second heat.

They can expect a response from the stung US crew, who have won all the major regattas they have entered for the last decade.

New Zealand have four crew members back from the boat which placed fourth at Rio last year - Dyke, Scown, Bevan and Tew.

The same foursome were in the eight who won silver at the 2015 world championships in France.

The men's eight couldn't repeat the dose on Wednesday (NZT), finishing fourth in a heat dominated by Olympic silver medallists Germany.

Stephen Jones, Brook Robertson, Michael Brake, Shaun Kirkham, Isaac Grainger, Patrick McInnes, Drikus Conradie, James Lassche and cox Caleb Shepherd will contest the repechage.

Fifth early on, they struggled to make headway in the quicker of the two heats.

Five rowers and Shepherd are all back from the Kiwi crew who were sixth at Rio.