The 28-year-old Yong scored in the 35th minute of the first half and another one in the second half, while CK Vineeth found the net in first three minutes of game.
The Lajong forwards, including Brazilian Uilliams Bomfin, could not breach the rival defence as Bengaluru FC routed the visitors in a one-sided match at the Sree Kanteerava Stadium.
With their third consecutive win, Bengaluru ended at number one place with nine points in the league, toppling Mohun Bagan who have six points from two matches.
The hosts were in control of the match soon after Vineeth scored a superb goal, a left-footer which defeated the Lajong goal-keeper in the third minute of the game.
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Bengaluru constantly attacked the net of the Lajong and missed a few more chances thereafter, until in 35th minute when Yong came to the party, scoring a goal of a deflection from the Lajong goal-kepeer, which helped the hosts take 2-0 lead.
Vineeth orchestrated a magnificent passing shot to Eugenon Lyngdoh who aimed to pierce through the Lajong goal- keeper, who handsomely saved the kick, but could not stop the North Korean from scoring his first goal for his club.
Soon, Yong once again struck delightfully to make the crowd go berserk with a magnificent third goal for Bengaluru, his second in the debut match.
Yong would have struck his hat-trick in 82nd minute, but missed as he hit wide off the goal-keeper.
The North Korean was declared man of the match.