New Zealand are still unbeaten despite suffering from a few first-round splutters A new strain of 'Sars' swept through the Hong Kong Stadium yesterday. It was the Stars-At-Risk-Syndrome and it claimed favourites England and South Africa, and almost spread in the direction of defending champions New Zealand. In two of the biggest upsets in recent years, England, champions at the past three Hong Kong Sevens, saw their record tainted when they were beaten by France (28-17) in their last match of the day in pool B. Earlier in the day, South Africa lost to impressive Tunisia (19-12) in their opening game in pool D. The virus almost claimed New Zealand too as Tonga put the pressure on by taking a 12-7 lead at half-time. However, big flanker Josh Blackie settled the nerves with the first score after the break which gave new heart to the Kiwis, who went on to win 19-12 in pool A. 'What today proved is that no team is invincible in sevens. This is a good wake-up call for us. We played poorly. But a win is still a win,' said New Zealand coach Gordon Tietjens. Otago Highlanders flanker Blackie was a tower of strength as he won key possession against the tough-as-teak Tongans, who had caused consternation among the Kiwi fans when Joseph Kolokihakaufisi and Tevita Tu'ifua scored early tries. Blackie's presence showed the way for the All Blacks, who picked their game up and quickly found the winning groove. 'We needed more commitment in the tackle and we had lapses of concentration,' said Tietjens. 'We will have to play better tomorrow as it is a big day for us.' Earlier in the day the New Zealanders' first-up tackling had looked a bit suspect in their opening encounter against South Korea, even though they looked majestic in attack when scoring seven tries. The Kiwis won the match 47-0. New Zealand will face the US and eighth seeds Scotland today, who are the other unbeaten team in the pool. The Scots yesterday defeated Ireland (33-14), South Korea (33-15) and the US (36-14). Blackie, one of two Super 12 players in Tietjens' young outfit, was outstanding against the Irish. He scored four tries in the 52-5 victory and showed he could play a crucial role as New Zealand attempt to defend their title against a host of predators. A revitalised Fiji look to be their biggest threat based on the opening day's matches. 'I was happy with the way Josh played. All the forwards will have to play a big role if we are to go all the way. Winning this World Cup will need a 12-man squad effort,' said Tietjens, pleased that his decision to draft in Blackie is already paying big dividends. 'At this stage it is hard to identify which players will make my frontline for Sunday,' said Tietjens. 'Everyone is getting a run in the pool games. I'm giving all the players as much game time as possible.' Tietjens said he was pleased that his side, led by the 20-year-old Liam Messam, was quickly into stride. Blackie, who played at the Hong Kong Sevens in 2002 before catching the eye of the Highlanders, crashed over for three first-half tries as the Kiwis turned on the pace and style against Ireland. Orene Ai'i and Rudi Wulf, the other Super 12 star in the team, added further tries as New Zealand led 31-0 at the break. The big and bustling Blackie added his fourth try midway through the second half before being substituted. He looks the part and will play a huge role in Tietjens' plans. 'It is just awesome to be a part of the World Cup. I'm privileged to be part of the team,' said Blackie. Unlike his more famous Super 12 peer Joe Rokocoko, who opted to stay at home with the Auckland Blues, New Zealand will be thankful for Blackie. His presence warded off Sars in the Kiwi camp.