Al-Ettifaq deepened Al-Nassr's suffering with a second goal in first-half stoppage time on Tuesday in the third round of the Saudi Roshn League.
Álvaro Medrán struck in the 45+3 minute, punishing the chaos that had gripped Al-Nassr's ranks after first-choice goalkeeper Bento was sent off, a dismissal that forced the team to turn to their young keeper Abdulrahman Al-Otaibi.
The inexperienced Al-Otaibi quickly became a target. Al-Ettifaq peppered him with shots from all distances and angles, exploiting both the loss of the first-choice keeper and the substitute's struggle to cope with the hosts' pressure.
Medrán fired towards the Al-Nassr goal in the closing moments of the half, and the ball nestled into the net to double Al-Ettifaq's lead, sinking Al-Alami's players and fans.
Slovak star Duda had opened the scoring in the 31st minute. Al-Nassr's players failed to close him down, and he let fly with a shot that looked tame but slipped through Al-Otaibi's hands and into the net.
Al-Nassr's night had turned sour back in the 12th minute, when Bento was shown a straight red card for fouling Moussa Dembélé outside the box.