Sporting Club de Goa did not even pose a threat to the confident I-League debutant from Meghalaya as the host dominated proceedings.
The Santosh Kashyap-led Royals made the first breakthrough in the 40th minute even as their previous attempts at the net did not fructify.
At the 20th minute, a Densil Theobald shot from outside the box had beaten the keeper but hit the crossbar.
Kashyap was rewarded with a goal two minutes later when a lunging Seityasen finished off a great cross from Lallawnzuala giving the much needed lead before the break.
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Resuming after the lemon break, the visitor's were on their toes but only to be punished for failing to check Kim Seong-Yong.
Yong headed home the second goal for Wahingdoh in the 58th minute as Sporting's tactics got depleted.