Ranty Martins's double strike gave Dempo a 2-0 victory over Mohun Bagan in a fifth round match in the ninth National Football League in Margao, Goa, on Tuesday.
The victory enabled the Goa side maintain their unbeaten run in the league.
Playing with authority, Federation Cup champions Dempo controlled the midfield and drew first blood in the 17th minute.
R C Prakash, from the left laid a pass to Clifford Miranda, who centered the ball into the box. The ball deflected off a defender and Ranty made no mistake in heading into the net after 'keeper Prasanta Dora hesitated to collect the ball.
Dempo kept the rival defence under pressure with a steady flow of passes and increased the lead in the 62nd minute when a move on the left saw Prakash getting the better of two rival defenders and laying a perfect cross to Ranty, who headed home from close.
The Bagan coach made a couple of changes in the midfield in the second half by bringing in Dulal Biswas and Abhay Kumar but the move could not fetch any results.
Bagan striker Roberto Mendes Silva, who was kept quiet, managed to sneak in and get the better of his marker in the dying minutes but his well-directed header was saved by 'keeper Dempo Satish Kumar.
Dempo are on top of the league table with 13 points from five matches while Bagan, who lost their second match, remain on seven points from five matches.