Iran made a winning start to qualifying for the 2022 World Cup with a 2-0 victory over Hong Kong on Tuesday while Brazil-born striker Elkeson scored twice on his debut for China in a 5-0 win over the Maldives.
Seeking a sixth World Cup appearance and third in a row, Iran picked up maximum points in their Group C opener after seeing off a determined and defensive Hong Kong, whose jeering fans drowned out the Chinese national anthem before kickoff.
Azmoun gave Iran the lead midway through the first half with a low volley into the bottom corner before Ansarifard secured the win with a side-footed finish nine minutes after the break.
"We gained three points from this match, so I think it was a positive result," said coach Marc Wilmots, who was taking charge of his first competitive game for Iran.
"We encountered a wall of defence from the Hong Kong team but we were able to score two goals and had opportunities to score more.
"This is the beginning of our preparations and we will get better day-by-day."
Iran are a point behind group leaders Bahrain who won away to Cambodia 1-0 but have played one game more.
Elkeson made his debut for China after switching nationality and the Guangzhou Evergrande striker scored twice -- including one from the penalty spot -- as Marcello Lippi's side eased to victory over the Maldives in Male in Group A.
The Chinese are now level on three points with the Philippines, who bounced back from their opening-round loss against Syria to thrash Guam 4-1.
Japan, another of Asia's World Cup regulars, also picked up a 2-0 win as goals from Shoya Nakajima and Takumi Minamino were enough to see off Myanmar in Yangon in Group F. Tajikistan top the group after they picked up a second straight win with a 1-0 victory in Mongolia.
In Group G, the United Arab Emirates fought back from going a goal down after 33 seconds to defeat Malaysia 2-1 in Kuala Lumpur thanks to a brace from Ali Mabkhout.
Bert van Marwijk's side join the Malaysians on three points and trail group leaders Thailand by a point after Akira Nishino's team beat Indonesia 3-0 in Jakarta.
Yemen led twice against Saudi Arabia and were dreaming of major shock against the five-times World Cup qualifiers, but Salem Al Dawsari earned Herve Renard's side a 2-2 draw in their Group D opener. Singapore, meanwhile, pulled off a 2-1 victory over Palestine.
Australia secured a comfortable 3-0 win over Kuwait in their first qualifier in Group B while Anjan Bista scored twice as Nepal handed Taiwan a 2-0 defeat.
In Group E, India held Asian champions Qatar to a 0-0 draw in Doha and Afghanistan notched up a 1-0 victory over Bangladesh.
Jang Kuk Chol scored the only goal as North Korea defeated Sri Lanka to move onto six points in Group H, three ahead of South Korea, who kicked off their campaign with a 2-0 win over Turkmenistan.
The eight group winners and the four best runners-up advance to the third round of qualification.