Three-time AFC Champions League champion Suwon Bluewings suffered elimination on away goals despite beating Kashiwa Reysol 2-1 in the last 16.
Kashiwa won the first leg 3-2 and secured its place in the quarter-finals thanks to midfielder Yusuke Kobayashi's 65th-minute strike, which proved to be enough after Jong Tae-se and Koo Ja-royng had given Suwon a 4-3 aggregate lead.
While Suwon's hopes came to an end, its K-League rival Jeonbuk Motors progressed 2-1 on aggregate over Beijing Guoan courtesy of a 1-0 success in the Chinese capital.
Brazilian forward Edu scored the decisive goal in the 72nd minute before Zhou Ting was sent off for the host in stoppage-time.
Just five days after its capture of Barcelona star Xavi was confirmed, Al Sadd suffered disappointment as it exited the ACL at Lekhwiya.
Trailing 2-1 from the first leg, Al Sadd looked set to force extra-time as it came from behind to lead 2-1 on the night.
Youssef Msakni put Michael Laudrup's Lekhwiya ahead in the 13th minute but, after the host was reduced to 10 men when defender Ahmed Yasser was dismissed in the 34th minute, Muriqui and Ali Assadalla turned things around for Al Sadd.
However, there was a final twist in the tale as Ismaeel Mohammad netted seven minutes from time for Lekhwiya to give it a 4-3 aggregate win.
Al Hilal cruised into the last eight with a 3-0 win home win against Persepolis, which had Mehdi Taremi sent off late on, ensuring a 3-1 victory on aggregate.