Australia had a mixed day in the first round of heats at the world rowing championship in Eton, England, with only three of seven boats qualifying at their first attempt.

Successfully leading the way was the flagship men's coxless pair of two-time Olympic champion Drew Ginn with his new partner, Atlanta Olympic bronze medallist Duncan Free.

The duo showed their composure and international racing experience by recovering from a slow start then putting in a burst of pressure to race ahead of the field and then control the pace of the race and score a measured win, nearly a boat length ahead of the other qualifier from their heat, China.

The time of 6min 30.82 secs was the slowest of the three heats, with 2005 world champion pair from New Zealand and the South African crew both finishing faster.

Australia had started the day in the best possible way with the women's coxless four winning the opening race of this eight-day regatta to earn a final berth.

The third Australian qualifier was the women's double scull of Liz Kell and Brooke Pratley, who showed great racing skill and composure for a new young team to score second place behind Belarus - the first three place-getters progressing in this class.

The women's coxless pair came closest to qualifying with a fighting second place to Canada, losing by just 3.51 seconds but looked a strong chance for qualification in their repechage.

The men's coxless four, men's double scull and women's single scull all came fifth in their respective heats and will need to improve to qualify later in the week.

The other half of the boat classes on the world championship program has their heats on Monday, when Amber Halliday and Marguerite Houston will race in the women's lightweight double scull.

Last Friday six Australian rowers across six different crews fell ill with food poisoning. They were the men's eight, double scull, lightweight coxless pair and the women's eight, coxless four and quad scull.

The regatta is being held at the venue for the London 2012 Olympic Games.

AOC