Al Hilal will need to come from behind in their tie with Persepolis in order to maintain hopes of winning the AFC Champions League.
A 92nd-minute own goal saw two-time AFC Champions League winners Al Hilal suffer a 1-0 defeat in the first leg of their last 16 tie at Persepolis.
The Saudi side were reduced to 10 men when midfielder Salman Al Faraj was sent off for a second bookable offence in the 88th minute.
And four minutes the later the numerical advantage for the Iranian team told when Brazilian defender Digao turned Mehdi Taremi's cross into his own net.
Lekhwiya came through in all-Qatari clash to win 2-1 at two-time champions Al Sadd.
Goals from Sebastian Soria and Youssef Msakni gave Lekhwiya a 2-0 lead before Hassan Khalid reduced the deficit for Al Sadd.
Despite Lekhwiya having Luiz Ceara sent off two minutes from time, Al Sadd were unable to complete the comeback.
Suwon Bluewings, winners in 2001 and 2002, will also have to come from behind following a 3-2 defeat to Kashiwa Reysol.
Yeom Ki-hun turned home Jong Tae-se's near-post cross to put Suwon ahead after two minutes, but Akima Barada levelled before Leandro's double - the first of which came from the penalty spot - put the visitors in command.
Jong pulled one back for the K-League side in the 59th minute to give Suwon hope for the second leg.
Elsewhere, Beijing Guoan netted a precious away goal in a 1-1 draw at Jeonbuk Motors as Pablo Batalla's 85th-minute penalty cancelled out Kim Ki-hee's opener for the hosts.