Having narrowly lost the earlier encounter in Kunming 2-1, Singapore would have been confident of their chances against China, but were instead put to the sword by an excellent Chinese outfit, with goals coming from Yu Hai, Li Weifeng and a brace from Zeng Cheng.
Within the first minute, China had an excellent opportunity when a long ball over the top found Yu clean through on goal down the left. However, with just Lionel Lewis to beat, the Shaanxi Renhe winger sent his shot narrowly wide from an acute angle.
Buoyed by their early opening, China continued to dominate initial proceedings, stroking the ball confidently around midfield, but it was Singapore who created the next half chance, when Fazrul Nawaz stormed down the left and cut inside on his right foot, but his shot was comfortable for Yang Zhi.
Barring that one chance for the hosts, China continued to dominate and force Singapore backwards, with Yu proving a handful down the left. In the 12th minute, Huang Bowen tested Lewis, sending a well-struck shot towards goal from just outside the area - but it was straight at the keeper.
Singapore were lively when they did manage to retain possession of the ball, and good link-up play down the right between Aleksandar Duric and the overlapping Noh Rahman created an opening for Firdaus Idros, forcing Yang to rush out and smother the ball.
Despite these occasional forays, China seemed most likely to open the scoring, and they created yet another glorious opportunity in the 24th minute when Gao Lin burst down the right and cut a clever pass back for Hao Junmin, who failed to control his half-volley, blazing it over.
Chen Tao was the next to try his luck for China when he was played through by Hao's incisive through-ball, but Lewis raced off his line well to bail his defence out once again with a good block.
Things got from bad to worse for Singapore in the 33rd minute when Shaiful Esah limped off, but it was the Lions who created the next opening after Firdaus created space for himself down the left with a sharp turn and sent in a dangerous cross which was just out of Duric's reach.
Nonetheless, China were eventually rewarded for their dominance three minutes before the break when they took the lead through the lively Yu. Hao and Chen Tao exchanged a couple of neat passes on the edge of the area, before finding Yu in space twelve yards out, and the 24-year-old made no mistake this time, sidefooting a shot past Lewis.
Despite trailing at the break, it was Singapore who started the second half the brighter of the two teams, with Lions captain Shahril Ishak showing signs of coming to life after a quiet opening period, while Firdaus continued to prove a handful down the right wing.
But it was China who created the first clear chance of the second period when Hao's long ball over the top found Yu once again. His initial shot was blocked, but he then unleased another left-footed effort which was only kept out by a firm right hand from Lewis.
However, Singapore came agonisingly close to an equaliser in the 53rd minute when Noh Rahman found space on the right and whipped in a dangerous low cross, which found its way into Duric's path. Despite the awkward bounce of the ball, the veteran striker pulled off a clever shot which had Yang beaten all ends up, only for his effort to come back off the crossbar.
Startled into action, China then pushed forward looking to consolidate their lead, and achieved that just three minutes later when captain Li rose highest to meet Hao's corner, before planting a firm header into the bottom corner, past Lewis' despairing dive.
With nothing to lose, Singapore started to push men forward and came close to pulling one back in the 66th minute when Firdaus forced Yang into a good stop after he had darted into the box to prod Duric's left-wing cross goalwards.
A minute later, China looked to have given their opponents a chance of salvaging something from the game when they were needlessly reduced to ten men. Having been on the receiving end of a hefty challenge from Mustafic Fahrudin, Huang Bowen responded by punching the Singapore midfielder in the chest, leaving referee Abdullah Baloushi no choice but to hand him his marching orders.
However, before Singapore had a real chance to make their numerical advantage count, China went 3-0 up in the 73rd minute thanks to a moment of brilliance from left-back Zeng. The Shandong Luneng defender, who had a solid game, picked up the ball in his own half and decided to go on a rampaging run, sprinting past a couple of challenges before finishing clinically past Lewis to all but seal the three points for his team.
And with Singapore spirits fully deflated, China then completed the rout in the 81st minute when Hao, who had pulled the strings for China all night long, held on to the ball long enough for Zeng to race in behind the Singapore defence before releasing the ball. From eight yards with only Lewis to beat, the left-back once again made no mistake.
There was still time for one last chance for Singapore to give the home fans something to cheer about, when an awkward ball over the top found Duric in space, but his powerfully-struck effort was well parried by Yang, capping off a miserable night for the Lions.
Singapore: Lionel Lewis, Noh Rahman, Daniel Bennett, Ismail Yunos, Shaiful Esah (Sevki Sha'ban 33'), Shi Jiayi (Isa Halim 46'), Mustafic Fahrudin, Firdaus Idros, Shahril Ishak Hafiz Rahim 72'), Fazrul Nawaz, Aleksandar Duric.
China: Yang Zhi, Zeng Cheng, Zhao Peng, Li Weifeng, Liu Jianye, Zhao Xuri, Hao Junmin, Huang Bowen, Chen Tao (Zheng Zhi 83'), Yu Hai (Yu Dabao 86'), Gao Lin (Zhang Chengdong 83').