Cristiano Ronaldo and Sadio Mane's Al-Nassr have won two and lost two of their first four games
Ex-Manchester United striker Ronaldo netted two penalties for Al-Nassr in their 4-0 win over Al-Shabab - and had a goal disallowed in between.
Ronaldo gave up a third penalty to Abdulrahman Ghareeb, but he missed.
The Portuguese set up Mane for a third and hit the post with a header, with Sultan Al-Ghannam netting the rebound.
Ex-Newcastle winger Allan Saint-Maximin set up former Manchester City player Mahrez to score the opener in Al-Ahli's 2-0 home win over Al-Tai, who had Alfa Semedo sent off in the 35th minute.
Mahrez then assisted Franck Kessie for the second goal as his side joined Al-Ittihad at the top of the table with four wins out of four.
-- Courtesy of BBC Sport