A superb free-kick from Yoon Bit-garam midway through the first half set Korea on their way at Changwon Football Center against GCC U-23 champions Oman before Kim Bo-kyung's angled strike with 16 minutes remaining sealed all three points in the Group A clash.
With only the group winners guaranteed qualification for London 2012, Ahmed Al Nahoyi netted with a minute remaining as Paulo Autuori avoided defeat on his debut as Qatar coach as his new charges claimed a 1-1 draw in Saudi Arabia.
Japan, meanwhile, made a winning start in Group C as Keigo Higashi and Ryohei Yamazaki scored to secure a 2-0 win over Malaysia in front of over 22,000 fans at Tosu Stadium.
Higashi produced a cool finish to round off a flowing team move after 10 minutes after exchanging passes with Hiroshi Kiyotake on the edge of the Malaysia area.
And Japan made the three points safe with 14 minutes remaining as Yamazaki turned home from close range after fellow second half substitute Kensuke Nagai had rounded off another expertly constructed Japan move by cushioning a header back across the face of the Malaysia goal.
With the runners-up in each group entering a three-team play-off for the right to meet an African representative for a trip to London, Mardek Mardkian scored twice as Syria moved to the top of Group C on goal difference after beating Bahrain 3-1 in Amman.
Finally in Group B, quick-fire goals from Temurkhuja Abdukholiqov and Kenja Turaev inside the final 20 minutes secured Uzbekistan a 2-0 win over Iraq in Tashkent, while in Adelaide, Australia failed to make home advantage count against the United Arab Emirates.
Both sides had their fair share of chances at Hindmarsh Stadium although the visitors, who won the silver medal at the 2010 Asian Games, could easily have claimed all three points as 2008 AFC Youth Player of the Year Ahmed Khail had a goal ruled out for offside in the first half before also coming close after the break.
The campaign to represent Asia in London next year continues in November with a key doubleheader on November 22, 23 and 27.
2012 Olympic Games - Final Round Qualifiers
21/09/11 Saudi Arabia 1-1 Qatar
Hussain Yahya Dagriri 12; Ahmed Al Nahoyi 89
21/09/11 Korea Republic 2-0 Oman
Yoon Bit-garam 24, Kim Bo-kyung 74
21/09/11 Uzbekistan 2-0 Iraq
Temurkhuja Abdukholiqov 71, Kenja Turaev 78
21/09/11 Australia 0-0 United Arab Emirates
21/09/11 Syria 3-1 Bahrain
Mohammed Fares 15, Mardek Mardkian 45, 54; Sayed Dhiya Saeed 85
21/09/11 Japan 2-0 Malaysia
Keigo Higashi 10, Ryohei Yamazaki 76