Cristiano Ronaldo scored a second-half winner as Al Nassr battled back from 2-0 down to keep their title hopes alive in the Saudi Pro League.
Cristian Guanca opened the scoring in the 24th minute from the spot after Luiz Gustavo was penalised for handball.
Guanca doubled their advantage in the 40th minute but Talisca reduced the deficit just before the break.
Winger Abdulrahman Ghareeb levelled in the 51st minute when he was left unmarked in the box to slot the ball home.
Ronaldo put his side 3-2 ahead in the 59th minute when he collected the ball outside the box and shrugged off two defenders before firing his shot past the keeper.
Leaders Al Ittihad beat bottom-of-the-table Al Batin 1-0 on Tuesday night.
There are now just two games remaining for each side in the season, with Al-Nassr trailing their rivals by three points with an equal goal difference but more goals scored.
Al Nassr will be hoping the leaders slip up in at least one of their two remaining matches.
They still have to face 12th-place Al Feiha and eighth-place Al-Ta'ee, while Ronaldo and his side will take on 10th-place Ettifaq before also facing Al Fateh