The Croatian, who was second behind Australia's Tom Burton at the Rio 2016 Games last month, won the first race of the day in light winds at the Beijing 2008 Olympic venue.

He followed that up with a third-place finish in race two and sits on top of the pile with a four point lead over Britain's Lorenzo Brando Chiavarini.

The Briton won race two after a seventh place finish in race one, with Ireland's Finn Lynch third overall.

"The first race was quite good from the start for me," said Stipanovic. 

"I wasn't sure what way the pressure was coming so I started in the middle and played it left or right depending on what I felt. 

"I was second at the upward mark then got in front of Finn [Lynch] and from there it was easy for me.

"The second race I started on the left and winds started to go right. 

"I was round the first mark in about 12th. 

"I managed to get myself up the fleet though and finish in third.”

Chiavarini won race two after a seventh place finish in race one, with Lynch second first up and then eighth.

In the women's laser radial, China's Dongshuang Zhang made the perfect start by winning both races.

That puts her top of the leaderboard after day one, with a three-point lead over compatriot Rubei Yuan.

In the men's RS:X, there was also a pair of wins for China's Chunzhuang Liu, who also came third in race three to top the pile on day one.

Manjia Zheng of China began her women's RS:X campaign with a disqualification but then won the next two races to claim top spot.

China's Mengxi Wei and Yani Xu sit at the top in the women's 470 fleet after their pair of wins on home water, with their compatriots Hao Lan and Chao Wang leading the way in the men's 470 class after a win and a second place finish.

A home sailor also leads the Finn class after Lei Gong claimed a first and a second place finish on day one.

Sailing continues tomorrow with action among all seven fleets being contested.