Major Asian football nations Saudi Arabia, Iran and China will face their first hurdles in the path toward Brazil 2014 when they start sudden-death home-and-away qualifiers Saturday, while Qatar has a challenging task as it seeks to assert its World Cup credentials. With only five nations given byes through to the third round of Asian qualifying, many teams with legitimate hopes of qualifying for Brazil will be thrust into action in second-round, first-leg games. The higher-ranked teams appear to have comfortable assignments on paper, but some have threatening opponents. Saudi Arabia has home advantage in the first leg when it faces Hong Kong. Having failed to qualify for South Africa 2010 — missing football's showpiece event for the first time since 1990 — the Saudis are under pressure to deliver. Qatar faces Vietnam, a nation whose passion for the game generally outweighs its performance but which will be confident after a 13-1 aggregate win over Macau in the first round of continental qualifying. Qatar will host the 2022 World Cup and is sparing little expense in trying to rapidly improve its national team, employing new coach Milovan Rajevac, who took Ghana to the World Cup quarterfinals last year. No. 50 Iran is the highest-ranked team forced into second-round qualifying, and will start as strong favorite when it hosts the Maldives. Nevertheless it would envy the free passage to the third round given to the five teams which performed best in 2010 World Cup qualifying: Japan, South Korea, Australia, North Korea and Bahrain. Neighboring Iraq — Asian champion in 2007— has a marginally more difficult match at home against Yemen. China is another nation expected to advance from its meeting with southern neighbor Laos, though China's national team has made a recent habit of failing to live up to expectations at key moments. It will be eager to make the most of its home game in the first leg, having seen Laos turn around a first-leg defeat by Cambodia in the first round by scoring six goals at home in the second leg. There are 15 second-round ties, with the winners to join the five pre-qualified teams in a third round comprising five groups of four. The top two teams from each of those groups will then go into a fourth round where there will be two groups of five, from which the top two in each group qualifies automatically for Brazil, and the two third-placed teams go into a further playoff. It is a marathon qualifying campaign, but one which many of the smaller nations would relish if they get beyond the second round, which will be completed with return legs on Thursday.