The 41-year-old Portugal superstar -- who had missed two league matches and an AFC Cup game earlier this month after reportedly going on strike in protest at his club's lack of January transfer business -- gave the home side an early lead after 13 minutes.
Kingsley Coman found Ronaldo in a crowded penalty area, where he took a touch with his right before clipping a left-foot effort back into the far corner. The goal was given following a VAR check for offside, which was Ronaldo's 500th since turning 30.
French forward Coman added a second on the half-hour after being set up by João Felix following a swift passing move and Ronaldo had another goal just before the break ruled out for offside.
Ronaldo scored a brace for Al Nassr against Al Hazem. Yasser Bakhsh/Getty Images
After Ronaldo was denied by another offside flag, Brazilian Angelo made it 3-0 in the 77th minute with a fine individual run from inside his own half.
Ronaldo finally got his second of the match with 10 minutes to go, latching on to a short pass from Coman into the left side of the penalty area before drilling in an angled drive.
Following another VAR review for offside, the goal stood as Al Nassr closed out an eighth straight league win, which moved them a point above rivals Al Hilal, who were held to a 1-1 draw at home by 10-man Al Ittihad.
