Al-Ettifaq hosts powerhouse Al-Nassr at Prince Mohammed Bin Fahd Stadium in Dammam for a high-stakes Matchday 3 encounter.
Al-Nassr suffered a major setback just 11 minutes into the match as goalkeeper Bento was shown a straight red card.
Following the dismissal, Al-Nassr manager Ange Postecoglou substituted Ângelo Gabriel to bring on backup goalkeeper Abdulrahman Al-Otaibi.
Midfielder Ondrej Duda capitalized on the numerical advantage, firing home in the 30th minute to put Al-Ettifaq ahead 1-0.
Cristiano Ronaldo and João Félix face a tough uphill task leading Al-Nassr's ten-man attack to mount a second-half comeback.
Both clubs entered Matchday 3 tied at six points, each striving to maintain early-season momentum at the top of the table.
Al-Ettifaq aims to protect their home advantage, while Al-Nassr pushes forward in search of an crucial equalizer.