I-League champions Dempo stormed into the semi-finals, while East Bengal and Sporting Clube de Goa registered hard-fought wins to stay in contention in the 34th Federation Cup.
Nigerian recruit Koko Sakibo struck a hat-trick (43rd, 79th and 90th) after captain Clifford Miranda opened the account in the 23rd minute for Dempo's 4-0 rout of Mumbai FC at the Keenan Stadium in Jamshedpur.
In a group C match at the Kanchanjungha Stadium in Siliguri, Sporting Clube de Goa kept their semi-final hopes alive with a hard-fought 3-2 win over a spirited Kalighat Milan Milan Sangha.
Later, East Bengal survived a scare by ONGC before rallying from a goal down to win 2-1.
Katsumi Yusa took advantage of an Uga Okpara faulty clearance in the 11th minute to give ONGC the crucial lead.
Much to their respite, East Bengal brought the equaliser at the stroke of halftime when Edeh Chidi converted a free-kick five yards from the ONGC box.
ONGC were reduced to 10 players after Yusa was sent off having picked his second yellow in the 77th minute as East Bengal got the winner three minutes later.
The East Bengal camp, who struggled in the midfield without the suspended Mehtab Hossain, finally got the much-needed goal through Manandeep Singh.
Sporting Clube and East Bengal now have four points apiece, although the former lead the group C table with a better goal difference.
East Bengal will face Kalighat MS, while Sporting Clube will take on ONGC in the last round Group C fixtures on September 25 to determine the semifinalists.
Dawson Fernandes (43th and 45+1st) scored twice including a penalty, while Macroy Piexote (12th) scored the first goal in Sporting Clube's win.
A spirited Kalighat MS scored through a brace by Christopher Chizoba (36th and 72nd).
Looking for their first win after a 1-1 draw against East Bengal in the first round, Sporting Clube gained the early advantage when Piexote breached the Kalighat citadel in the 12th minute.
Kalighat MS restored parity when Christopher scored from a powerful long ranger.
Dawson was brought down inside the box in the 40th minute but he converted from the spot to restore Sporting Clube's lead.
Minutes later, Dawson got into the act again finding the back of the Kalighat net with an angular finishing.
Sporting Clube's game went off track after the break to allow Kalighat to reduce the margin in the 72nd minute, when Chirstopher scored from a solo effort.
Dempo topped the group A table with seven points from three matches to make the cut, while Pailan Arrows (five) finished second ending their campaign with a 2-1 win over Shillong Lajong (three).
In the match played at JRD Sports Complex in Jamshedpur, Holicharan Narzary scored off a rebound in the 17th minute but Arrows's joy was cut short when Lajong striker Ebi Sukore equalised easily four minutes later.
The Kolkata outfit however kept on the pressure as they earned the all important winner in the 69th minute through Prabir Das who converted a floater from the left-wing.