BEIJING (Reuters) - Australia's men's quad set a world best time on Lake Shunyi on Sunday, before thunderstorms forced officials to suspend the Olympic rowing regatta for the rest of the day.

Australia held off Italy to win the first heat of the men's quad sculls and shave just over a second off the world best time recorded by a Polish crew in 2006.

Athletes said the strong tailwind made conditions tricky as they had to maintain perfect technique with the boats moving faster.

But the strong winds turned to thunderstorms and officials suspended racing with just the men's and women's eights races left to complete. They are yet to be rescheduled.

In the races that were completed, all the favorites progressed through to the next round.

Britain and China set up an enticing final in the women's quads races, with both crews winning easily.

"It was quite a composed row and we know that the Germans are unbeaten in the Olympic Games (in the women's quad) so we knew how they would be," Britain's Annie Vernon said after beating the Germans by over a second in the second heat.

In the men's lightweight fours Denmark and Germany both won their heats in new Olympic best times.

The Netherlands upstaged world champions Australia in the lightweight women's double event, Germany finished well to win their race and China took the third heat.

(Reporting by Kate Holton; editing by Jeremy Laurence)