Al-Ain became the first team to book a place in the Asian Champions League last 16 as the former winners beat Saudi Arabia's Al-Fayha 3-2 with two goals from Kodjo Laba on Tuesday to maintain their perfect start to this season's competition.
The United Arab Emirates side have 12 points from their first four games and are guaranteed to finish top of Group A despite having two matches to play after nearest rivals Pakhtakor of Uzbekistan drew 1-1 with Turkmenistan's Ahal.
Pakhtakor were reduced to 10 men in the 64th minute when Odiljon Hamrobekov was sent off and Alibek Abdyrahmanow gave Ahal the lead 17 minutes later only for Hojimat Erkinov to score an added time equaliser for the visitors.
The draw means both teams have four points and are battling for second place in the group.
Only the winners of the competition's 10 groups are sure to make the knockout rounds, while the three runners-up from the western and eastern halves with the best records also progress.
In Al-Ain, Laba gave the hosts a two-goal lead by the 40th minute before Anthony Nwakaeme reduced the deficit eight minutes into the second half but Soufiane Rahimi restored his side's cushion in the 64th minute.
Muhannad Al Qaydhi's goal six minutes into injury time was no more than a consolation as Al-Ain impressed again.
In Group E, Saudi Pro League side Al-Nassr brushed off the absence of Cristiano Ronaldo to beat Qatar's Al-Duhail thanks to Andersen Talisca's hat-trick as Luis Castro's side recovered from conceding a Philippe Coutinho goal to secure a 3-2 win.
Coutinho put the hosts ahead in the eighth minute when Michael Olunga capitalised on Mohammed Al Fatil's stumble to claim possession deep in the Al-Duhail half and set up the former Liverpool forward to score.
But Talisca netted twice in 10 minutes with a pair of low strikes from outside the area in the 27th and 37th minutes to give the side from Riyadh the lead at the break.
The Brazilian completed his treble in the 65th when he calmly converted Abdulrahman Ghareeb's lay-off and although Coutinho added a second from the penalty spot 10 minutes from time Al Nassr held on to win.
The Saudi side have 12 points from four games, five points ahead of Persepolis after the Iranians drew 1-1 with Istiklol of Tajikistan in Dushanbe.
Mehdi Torabi put Persepolis in front with a fine 29th minute free kick but Senin Sebai equalised 16 minutes from time.
The results mean Istiklol and Al-Duhail cannot qualify for the knockout rounds.