Goals from Joshua Walker (33rd minute), Rino Anto (51st), Thoi Singh (60th) and Beikhokhei Beingaichho (80th) meant the Blues kept the pressure on leaders Mohun Bagan whom they now trail by a sole point.
Ashley Westwood's men went into the game knowing nothing but a win would do after Royal Wahingdoh, who travel to the city in two days, scored a 1-0 win over East Bengal to move three clear of the Blues.
Chasing their first win of the season, Sporting were dealt a telling blow when captain Anthony Wolfe came off at the 30-minute mark with what seemed like a dislocated shoulder.
But it was Walker who sprung the game to life when he deftly headed a Eugeneson Lyngdoh freekick at the far post to give Bengaluru a lead they would take to the dressing room at half-time.
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Not wanting to take a foot off the pedal, Bengaluru found their second in the 51st minute after Sean Rooney did brilliantly well in setting up Rino. Set free with a long ball, Rooney sprinted down a fair bit of the pitch, held his marker off and slipped one through for an onrushing Rino who shot home from close.
With 10 minutes to the whistle, substitute Beingaichho kept his fluent goal scoring record against Sporting Clube intact when he picked up CK Vineeth's cut back and shot past Ravi Kumar.
Sporting Clube did get on the score sheet three minutes later through Victorino Fernandes but it would only be a consolation.