Al-Hilal doubled their lead over visitors Al-Gharafa of Qatar at the Kingdom Arena in the Saudi capital Riyadh, in the opening round of the AFC Champions League Elite.
Sergej Milinkovic-Savic made it two in the 73rd minute, powering home a header after an excellent cross from teammate Ruben Neves.
Neves had opened the scoring from the penalty spot in the 45+3rd minute.
The 32nd minute brought a flashpoint. Al-Hilal's Crysencio Summerville clashed with Ismael Bennacer, who was making his debut in an Al-Gharafa shirt.
Tempers flared as players from both sides piled in, and the referee showed red cards to Summerville and Bennacer.