The draw left Mumbai on top of the league table with 23 points, a tally that none of the other qualifying teams can overtake.
Delhi Dynamos have 21 points from 14 matches and they will know of their position only after the concluding league clash between Kerala Blasters and NorthEast United FC in Kochi tomorrow.
The draw at Mumbai Football Arena also meant that the two teams -- Mumbai and Delhi -- will not meet in the semi-finals.
Delhi head coach Gianluca Zambrotta made as many as eight changes with marquee signing Florent Malouda on the bench, while Mumbai coach Alexandre Guimaraes had promised to field his best squad and he stuck to his word with a strong side.
More From This Section
India captain Sunil Chhetri was the only absentee as 20-year-old Udanta Singh made an impressive debut in the ISL.
Mumbai were the better team for the entire game, particularly in the first 45 minutes when they had six attempts on goal. Delhi had only one shot and none on goal.
In the second session, both teams went close to scoring and the match could have gone either way. Interestingly, both teams hit the post in successive minutes.
In the 72nd minute, Cafu picked up a ball just outside the box and took a snap shot on the Delhi goal which rattled the post with goalkeeper Doblas looking helplessly.
Mumbai's last chance to finish their engagements with a win at home came in the 83rd minute. Forlan's delivery was aimed at Lucian Goian who headed it across the face of goal.
Udanta thought he had a chance to head it home from close range, only for Brazilian defender Gerson Vieira to distract him and allow Doblas to collect the ball safely.