The maxim that attack is the best form of defence was turned on its head by Hong Kong who showed the best way to win at rugby sevens is to defend strongly. Rowan Varty and his men turned iron-clad defence into annihilating weapon as Hong Kong finished unbeaten with their goal-line intact on the opening day of the Mumbai Sevens at the Bombay Gymkhana Club. Three handsome wins over India (43-0), United Arab Emirates (42-0) and Thailand (66-0) have paved the way for a much-anticipated clash with arch-rivals Japan for the spoils in the third and last ranking leg of the HSBC Asian Sevens Series. The winners of today's final are expected to be crowned Asian champions, a title which carries with it the rewards of earning a berth against the core teams - the likes of New Zealand and Fiji - at next year's Hong Kong Sevens as well as an invitation to the final leg of the HSBC Sevens World Series in London. If Hong Kong defend as well as they did yesterday, those rewards are expected to fall safely into their laps at day's end today. "We seem to have a complete game now with the focus on defence where the aim is to win the ball back and score tries from that. This is something we did very well today," said a pleased Hong Kong coach Dai Rees. Hong Kong's tryline was as safe as Fort Knox and Rees' pride in a "complete game" was highlighted by the 21 tries scored yesterday with skipper Varty, Tom McQueen and Kwok Ka-chun to the fore in the touchdown stakes. "Defence wins tournaments but we didn't have a bad day in attack, either," Rees said. The real test will begin today with Hong Kong coming up against a resurgent Sri Lanka in the Cup quarter-finals and a projected semi-final clash against Taiwan. Sri Lanka, coached by former England sevens star Ben Gollings, pulled off a major surprise when they defeated a Malaysian outfit packed with Fijians early in the day. That has turned the form book upside down with pool favourites China ousted from the Cup competition. Rees hopes a similar surprise awaits Japan when they meet South Korea first up in their quarter-final. "We hope the fate of the series is decided before we enter the final," laughed Rees. He was referring to the fact that if Hong Kong meet Japan in the final, it would be a winners-take-all match with the winners being crowned Asian champions. But if Japan were to lose to either Korea, or Malaysia (their likely opponents in the semis) Hong Kong will be champions if they reach the final. "We cannot afford to look too far ahead. There are enough dangers. Sri Lanka who looked quite a good side," Rees said.