Ronaldo’s first goal came in the 77th minute when he controlled a loose ball on his chest and then expertly lofted it over goalkeeper Paulo Vitor from distance.
Three minutes later, Ronaldo doubled his lead with a powerful finish from a tight angle.
The 38-year-old’s goals took his tally for the season to 15, making him the league’s top scorer.
Midfielder Sami Al Naji had opened the scoring for Al Nassr in the 13th minute.
The victory was Al Nassr’s 11th from 14 games this season and moved it to second place in the table, one point behind Al-Hilal.
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