Leaders South Korea moved five points clear at the top of Group G courtesy of an emphatic 4-0 win over Myanmar at the Suwon World Cup Stadium on Thursday.
Uli Stielike's men were already in control of their qualification destiny for the World Cup in three years' time and strengthened their chances further with a convincing victory that saw Lee Jae-sung open the scoring 18 minutes in.
Jang Hyun-soo missed a penalty for the hosts midway through the half but Koo Ja-cheol secured South Korea a two-goal advantage at the break.
Stielike's side bolstered their goal difference in the second half but were made to be patient, Jang and Nam Tae-hee both on target inside the last 10 minutes.
Myanmar remain in the hunt for the Asian Cup qualifying third round while South Korea go five points clear with three matches to play after winning their game in hand.
The hosts began brightly, Kwak Tae-hwi forcing Myanmar goalkeeper Kyaw Zin Phyo into an early save with a header from a corner.
While the visitors steadied themselves amid early pressure, Lee lost marker Kyi Lin to collect a sublime cross-field pass and steer home the opener.
And when Jang was fouled by Phyo Ko Ko Thein inside the area he had the chance to double the lead from the spot, only to hit the post before failing to react to the rebound.
The pressure continued and the home side eventually doubled their lead half an hour in courtesy of Koo's powerful header from inside the box.
Ki Sung-yueng's long-range drive was tipped wide by Phyo before Hwang Eui-jo's prodded effort over the crossbar proved the final chance of the half.
As South Korea struggled to convert their dominance into further goals, Stielike introduced Tottenham's Son Heung-min just prior to the hour - the forward having recently recovered from a foot injury.
Kim Jin-su blazed an effort high and wide when free down the left while a last-ditch clearance denied Kyaw Ko Ko a sight on goal following a long hopeful ball forward from the visitors.
Jang eventually made amends for his penalty miss when he glanced home a free-kick from inside the area eight minutes from time with Nam adding a fourth soon after.
A cool finish from the Lekhwiya midfielder, following a slick move, rounded off the scoring and completed a convincing win as South Korea took another step towards a ninth consecutive World Cup finals ahead of their final game of a successful 2015 against Laos on Tuesday.