Sporting desperately needed a win to breathe fresh air and scored through Mehrajuddin Wadoo (2nd minute), Sumeet Passi (21st, 33rd), Subhasish Bose (65th) and Mahmoud Al Amna (89th) to take their tally to 18 points from 14 matches.
While Pen Orji score twice for Shillong Lajong to remain on 15 points from 14 matches. They are placed fifth.
Sporting, who put up a poor performance in their last match, made three changes bringing in Ganesh Thakur, Sumeet Passi and Pratesh Shirodkar in place of Efemena Charles, Marcus Mascarenhs and Denson Devadas.
The home team attacked with more vigour and increased the lead in the 21st minute. Pratesh Shirodkar, from the left, floated the ball into the box for Sumeet Passi who leaped high and nodded the ball into the net.
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The visitors got a jolt when striker Uilliams Souza Silva got marching order from Santhosh Kumar in the 29th minute after he verbally abused the referee for showing yellow card for a foul on Mahmoud Al Amna.
After the break, Sporting continued to enjoy possession and scored two more goals to end the contest.
Rowllin Borges, who controlled the midfield, floated the ball from a free kick and defender Subhasish Bose found the net with a clean header from inside the box.
As Sporting continued to threaten the rival defence with repeated forays, Orji scored two smart goals to bring his team into the contest before Amna scored from a penalty to give Sporting Clube de Goa their biggest victory in the tournament.