The Norwegian, a single sculls winner at Athens 2004 and Beijing 2008, has since returned to the double sculls event in which he won his first Olympic medal, a silver, at Sydney 2000.

He and partner Kjetil Borc finished comfortably clear to win their heat and qualify directly to the final.

Marko Marjanovic and Andrija Sljukic of Serbia joined them by winning the second heat.

Ilse Paulis and Maaike Head of The Netherlands were among other impressive winners on Swiss waters.

They won the lightweight double sculls heat in 6min 54sec - just six seconds outside of the World Best Time.

Frederique Rol and Patriia Merz excited the home crowd with Swiss victory in the second heat after battling past Greek opposition.

In her first international race since her 2014 World Championship win, New Zealand's Emma Twigg won her single sculls head in 7:31 after fending off British rival Mathilda Hodgkins-Byrne.

Sanita Puspure of Ireland beat six-time Olympian Ekaterina Karsten of Belarus to win heat one, while the other was taken by Fie Udby Erichsen of Denmark. 

There was more Danish solo success in the men's singles sculls as Sverri Nielsen joined France's Cedric Berrest and Hannes Obreno of Belgium in winning heats.

London 2012 Olympic champions Rasmus Quist and Mads Rasmussen were among other winners today in the lightweight double sculls event.

A Ukrainian quartet much-changed from the team which claimed Olympic gold in London were beaten by China - the country that claimed Beijing 2008 gold - in the women's quadruple sculls.