The event in Plovdiv began today ©World Rowing

Croatia's Martin and Valent Sinković made a promising start to their season as they won the first men's pair heat on the opening day of the World Rowing Cup in Plovdiv.

The world champions, gold medallists in the double sculls at the 2016 Olympic Games in Rio de Janeiro, clocked a time of 6min 32.890sec to book their place in the final in style.

It marked the start of what they hope is a successful return to the venue where they clinched the world title last year.

The Croatian joined by Serbia's Martin Mackovic and Milos Vasic, who won the second heat in 6:26.900.

There was further success for Croatia as Olympic silver medallist Damir Martin triumphed in his men's single sculls heat.

There was further success for Croatia as Olympic silver medallist Damir Martin triumphed in his men's single sculls heat ©World Rowing
There was further success for Croatia as Olympic silver medallist Damir Martin triumphed in his men's single sculls heat ©World Rowing

Martin crossed the line in a solid 6:49.25 to qualify for the final.

Miroslava Knapková of the Czech Republic, the London 2012 Olympic champion, won her women's single sculls heat in 7:28.500.

The 39-year-old was in superb form as she eased into the final.

Belarus' Ekaterina Karsten, the 46-year-old double Olympic champion who has come back to the women’s single after competing last year in the women’s quadruple sculls, failed to qualify directly and will have to go through the repechage.

The first set of finals are due to take place when the event resumes tomorrow.