Iraq League champions Arbil, Syrian champions Al Karama, Kuwait's Al Arabi, Kuwait Sports Club and Uzbekistan's Neftchi advanced to the quarter-finals of the AFC Cup.
Arbil beat compatriots Al Zawra'a 3-1, Al Karama edged out Bahrain's Busaiteen 2-1, while Al Arabi needed extra-time to advance at the expense of Lebanon's Safa.
Jehad Al Hussien's second hat-trick of the competition helped Kuwait SC eliminate India's Dempo, while Neftchi earnt a goalless draw in Syria against Al Maged before prevailing 3-1 on penalties.
At Al Maktoum Stadium in Dubai, Ahmed Salah headed Group C runners-up Arbil ahead a minute before the break before another header, this time from Luay Salah, doubled the advantage just after the hour mark.
Ahmed Abd Ali added a third with 20 minutes remaining after capitalising on a goalkeeping error before Adnan Atiyah grabbed a consolation for Group B winners Al Zawra'a.
At the Bahrain National Stadium in Mamama, Hassan Abbas' strike with four minutes remaining in extra-time helped Group D runners-up Al Karama down Busaiteen, who had advanced to the last 16 with an unbeaten record from Group A.
Robert Akuraye earned Busaiteen extra-time with 12 minutes remaining after cancelling out Mohamad Al Hamwi's opener just before the break, but with penalties looming, captain Abbas' spectacular strike sent Al Karama through.
At Sabah Al Salem Stadium in Kuwait City, Firas Al Khatib's winner with eight minutes remaining in the second period of extra time sent Group C winners Al Arabi through as Safa failed to follow up last year's run to the final.
Nigerian midfielder Emmanuel Ezukam opened the scoring for Al Arabi 29 minutes into the first half and after Ali Al Saadi levelled for the visitors a minute before the hour, Al Khatib rounded off a counterattack to avoid a shoot-out.
Also in Kuwait City, Syria international midfielder Al Hussien followed up his hat-trick against India's other representative, Mohun Bagan, to help Group D winners Kuwait SC through.
Group E runners-up Dempo had pulled a goal back through Brazilian midfielder Beto with 17 minutes remaining before Al Hussien secured his side's place in the last eight with a second penalty of the match in stoppage time.
Finally in Damascus, Al Maged's Mohammad Al Zino wasted a string of chances as the Group E winners failed to find a way past Neftchi in 120 minutes at Al Abbassiyin Stadium.
And in the shoot-out he saw his penalty saved by Neftchi goalkeeper Yuriy Tsoy before Mouhanad Asaad and Bashar Al Kaddour missed from the spot as the Uzbek side, who finished runners-up in Group A, advanced.