Japan moved into first place on the standings in Group E after claiming a 3-0 victory over Syria in Muscat on Thursday, while India lost their fourth consecutive 2018 World Cup qualifier as they went down 2-1 to Turkmenistan.
Vahid Halilhodzic's Japanese team were left frustrated in the first half against a Syrian side that won all three their previous 2018 World Cup/2019 Asian Cup qualifiers, before Keisuke Honda broke the deadlock with a 55th minute spot kick following an infringement in the hosts' penalty area.
Leicester City striker Shinji Okazaki looked dangerous throughout the match and finally got the goal his performance deserved in the 70th minute after being played in by BVB Dortmund ace Shinji Kagawa.
Second half substitute Takashi Usami then put the result beyond doubt two minutes from full time with a goal of his own.
The result leaves Japan on 10 points in Group E, one ahead of their opponents on Thursday, while Singapore are in third place, another two points behind.
In Ashgabat, India suffered yet another loss as they remain rooted to the foot of the table in Group D.
The hosts took the lead in the eighth minute, somewhat against the run of play, when midfielder Guwanc Abylow received the ball in a bit of space in the Indian box and made no mistake with the cool finish.
To their credit, India kept plugging away at the Turkmenistan and proceeded to level the score in the 28th minute through Jeje Lalpekhlua.
The visitors were arguably the better side in the first half, but after the half-time interval their level of performance dropped somewhat and on the hour mark, the hosts were back in front thanks to a fine strike from Arslanmyrat Amanov.
Despite their victory on Thursday, Turkmenistans' chances of advancing are slim – they are on four points after four matches in Group D and trail Iran, Oman and Guam by three points or more.
In Thimphu, Maldives beat Bhutan 4-3 at the at the Changlimithang Stadium thanks to a hat-trick of goals by captain Ali Ashfaq.
Ahmed Nasheed opened the scoring for the visitors on 11 minutes before Ashfaq scored twice before the half-time break to hand Maldives a 3-0 lead.
The 30-year-old veteran striker then completed his hat-trick seven minutes after the break, but with the score on 4-0, Maldives took their proverbial foot off the pedal and nearly paid for their slackness.
In the final five minutes, the hosts scored thrice with goals from Tshering Dorji, Chencho Gyeltshen and Biren Basnet nearly giving Bhutan an unlikely draw.
Lebanon kept their hopes of advancing to the next stage of qualifying alive with a 2-0 victory at Myanmar.
Hassan Maatouk gave the visitors the lead in the 28th minute, before Abbas Ahmad Atwi secured all three points for Lebanon with a stoppage time goal of his own.
Lebanon are in third place in Group G, three points behind Kuwait and six points adrift of Korea. Myanmar, meanwhile, are languishing in last place with one point.
Earlier, Palestine and Timor-Leste played out a 1-1 draw in their Group A qualfier in Dili.
Timor-Leste took the lead in the 54th minute courtesy of defender Ramon Saro, before an injury time Ahmed Abunahia secured a share of the points for Palestine.
The result leaves Palestime in third place in Group A on five points, while Timor-Leste are in fourth, three points further behind.