World Series leader New Zealand is the favorite to win the Hong Kong Sevens this weekend, but in a season that has proved unpredictable there's plenty of room for an upset.

"With the atmosphere and the vibe here, Hong Kong is regarded as the biggest tournament in the world," said South Africa coach Paul Treu.

Second in the World Series overall standings, South Africa is one of the main challengers for the Hong Kong crown.

"We've won all the tournaments all over the world, but for the past 20 years this one has eluded us. Hopefully we'll have some luck this time around," Treu said.

South Africa defeated New Zealand 40-21 to take the Las Vegas Sevens last month, but Treu remained cautious going into Hong Kong.

"The biggest mistake that you can make is to come off a win and expect to win. We need to keep our feet on the ground," he said.

AFP