After James Moga cancelled Ranty Martins 9th minute goal in the 37th minute, Ranty scored three more goals in the second half to end Sporting Clube de Goa challenge.
The win takes Dempo tally to 53 points from 24 matches, 12 points clear of East Bengal which is the only team that can challenge Dempo for the title race as they have four matches to play.
Sporting remained on 37 points from 24 matches.
Dempo made their intention clear from the start as they held better ball possession in the early part of the match and Denzil Theobald forced rival keeper Ashok Singh to make a diving save off Koko Sakibo back pass in the 9th minute.
Ten minutes later Ashok Singh again came to his side's rescue when he made a diving save to put the ball out off Koko Sakibo shot off a pass from Theobald.
Sporting citadel finally fell in the 22nd minute when Ranty Martins half volley from the top of the box found the far corner of the net off Koko pass.
Sporting who matched their fancy rivals well in the first half came with few raids but Freiman Peixoto and Adil Khan shots lacked the direction to find net.
However, their persistent efforts in search of the equaliser bore fruit in the 37th minute when James Moga header found the net off a flag kick taken by Anthony D'Souza.
Changing over, Dempo turned the heat on their rivals and Ranty Martins scored two goals in a span of two minutes to score a hatrick and take his tally to 30 goals to lead the score chart.
Sporting defence was found napping when Koko released the ball to Ranty Martins inside the box who beat two rival defenders and shot home in the 50th minute.
Ranty Martins again scored in the next minute when he beat defender Boboi Singh and shot home from close off a pass from Koko Sakibo to snuff up Sporting challenge of any come back.
Ranty Martins who is the leading scorer then hit the last nail in Sporting's coffin when he tapped home from close a cross from Anthony Pereira from the right to take his tally to 31 goals.