North Korea, Qatar, Thailand and Jordan all won on Tuesday to maintain their group leads in the second round of Asian qualifying for the World Cup.
Jong Il Gwan's 12th-minute penalty gave North Korea a 1-0 win over Yemen in Group H.
The North Koreans opened a four-point lead over Uzbekistan, who have a game in hand.
In the other Group H game, Ismail Abdul-Latif and Sayed Adnan both scored early in the second half to give Bahrain their second win in qualifying, 2-0 at home against the Philippines.
Qatar cruised to a 4-0 win at home against Maldives as the 2022 World Cup hosts continue to enjoy a five-point lead in Group C.
Boualem Khoukhi scored twice, and Qatar also received goals from Mohammed Kasola and Mohammed Musa.
Hong Kong kept pace with a 1-0 win over minnows Bhutan, though they were made to wait until Siu Ki Chan's 89th-minute winner.
In Group F, Thailand beat Vietnam 3-0 at Hanoi to move five points clear of Iraq, who have played a game less.
Kroekrit Thaweekarn scored in the 29th minute, an own goal 10 minutes after the break by Dinh Tien Thanh made it 2-0, and captain Theeraton Bunmathan added a third in the 70th minute.
Jordan maintained their lead in Group B with a 3-0 win at home over Tajikistan, Hamza Aldaradreh recording a brace and Hasan Abdel Fattah also scoring.
Kyrgyzstan stayed in the Group B hunt with a 2-0 win at home over Bangladesh thanks to goals from Vitalij Lux and Ildar Amirov.
Oman opened a three-point lead in Group D with a 3-0 win at India, who have lost all five of their qualifiers so far.
Abdul Aziz Al Muqbali scored twice following Ahmed Al Mahajri's opener 10 minutes after half-time.
After a flying start to their campaign, Guam stuttered again in a 1-0 loss at Turkmenistan, Guvanch Abylov scoring the only goal in the 16th minute.
Despite playing all of the home games in Oman, Syria took the lead in Group E with a 5-2 win over Afghanistan as Osama Omari scored a hat trick and Mahmoud Al Mawas scored two more.
Afghanistan had cut Syria's lead to 3-2 by the 78th minute through goals from Norlla Amiri and Faysal Shayesteh.
Singapore won their third game of the campaign with a 2-1 victory at Cambodia after Faris Ramli and Fazrul Nawaz scored.
Kuwait missed a chance to overtake South Korea for first place in Group G following a goalless draw at home with Lebanon.
In the other game in Group G, Myanmar defeated Laos 3-1 with goals by Lam Mang Suan, Ko Ko Kyaw and Aung Thu.
Mohd Amri Yahyah scored Malaysia earned their first win of the campaign with a 1-0 victory at winless Timor-Leste in Group A.
The eight group winners and four best runners-up will advance to the last round of Asian qualifying.
Asian giants Australia, Japan, South Korea, Iran and China were among the teams not playing on Tuesday.