The Nigerian forward scored two goals as Al Hilal defeated Al Nassr 2-0 to reignite their title hopes.
Ronaldo and his teammates arrived the game looking for a win to take them back to top of the table, but Ighalo had other ideas, producing a fine performance in front of their own fans at the King Fahd International Stadium.
Al Hilal were awarded a penalty three minutes before half-time, and Ighalo converted the kick, sending Nawaf Alaqidi the wrong way.
The second half followed much of the same pattern as Al-Hilal were handed another chance to score from the spot just past the hour and Ighalo grabbed the opportunity with both hands to make it 2-0.
With the brace, Ighalo is top of the goalscorer’s chart with 18 goals and 2 assists – 7 goals more than Ronaldo, although the Portuguese has played fewer games.
Cristiano Ronaldo was frustrated all through the night as he was booked for lashing out and had a goal ruled out for offside moments later.
The 38-year-old thought he’d won his side a penalty via a handball when his free-kick was blocked, only for the decision to be overturned after a VAR review.
Following the result, champions Al Hilal remain fourth on the table, while Al Nassr are second.