NorthEast United are currently in second spot with 20 points from 11 games while ATK are still sixth with 16 points from as many games.
The result sees Bengaluru FC preserve their four-point advantage over NorthEast United at the top of the table.
NorthEast United pushed FC Goa down to the third position with a one-point lead.
NorthEast United FC continued their unbeaten run away from home and climbed to the second spot.
NorthEast United's are now placed third on the ISL table with 14 points from seven matches.
Mumbai City FC halted NorthEast United FC's unbeaten run in an Indian Super League.
The win over Delhi Dynamos gave NorthEast United their third win in five matches this Indian Super League (ISL) season.
Bartholomew Obgeche (20th minute) gave the hosts early lead before Farukh Chaudhary cancelled out his strike in the 49th minute.
Bartholomew Ogbeche scored a hat-trick for NorthEast United FC against Chennaiyin FC in an Indian Super League match.
Pune City lost 0-4 against Goa in their penultimate clash but their impressive performances earlier in the season means they don't have to wait for the final league clash to secure a point for a place in the play-offs.
Zequinha was the star of the show, striking in the 73rd minute to give his side the lead and the winner.
Pune have now moved to the second spot with 15 points from eight matches and are just a point behind league leaders Chennaiyin FC.
Balwant scored on either side of half-time to ensure a 2-0 win for the Mumbai outfit.
NorthEast United were dealt with a huge blow when their goalkeeper TP Rehenesh was sent off for a last-ditch tackle on Mark Sifneos.
The 47th minute strike was enough for the in-form table toppers to finish the game with three points at the Indira Gandhi Athletic Stadium.
This was Dynamos' second consecutive loss after their 1-4 thrashing by Bengaluru FC on November 26. They now have just three points from three matches.
Chennaiyin FC beat NorthEast United 3-0 in the match in Chennai on Thursday.
Chennai registered their first win at home over NorthEast United in the ISL and only their second victory over their North-East rivals.