Bounedjah, 27, grabbed his sixth hat-trick in his 21st league game in a 7-2 win over Al Ahli on Thursday, which took his total to 39 for the season.
The three points gave Al Sadd a seven-point lead over second-placed Al Duhail, the club of Morocco captain Medhi Benatia.
Atlas Lions star and club teammate of Benatia, Youssef Al Arabi, is the second in the race for the Golden Boot with 25 goals.
In a staggering personal campaign, Bounedjah also netted a double hat-trick, while his overall tally stands at 101 goal contributions (82 goals, 19 assists) in 61 games since his arrival from Tunisian giants Étoile du Sahel.
It marked Al Sadd's first league title since the 2012/13 season and record 14th title overall.
— Lorenz Köhler (@Lorenz07Kohler) April 5, 2019