A fortuitous goal from Ogba Kalu ensured full points for Churchill Brothers and a place in the semi-finals of the Osian's 121st Durand Cup as the Goa side beat Army XI 1-0 at the Ambedkar Stadium in New Delhi on Sunday.
Jogeshwar Singh's cross was headed by Kalu and Army XI goalkeeper Robikanta Singh allowed it to slip under his arms and over the goal-line in the 41st minute during the Group A quarter-final encounter.
The fate of Mahindra United and Mumbai FC will now be decided in the group's last round of matches after both drew 1-1.
Mahindra United, who meet Churchill Brothers, need just one point to advance to the last-four stage following their 3-0 win over Amy XI in their first match.
For Mumbai FC to progress, they have to beat the securitymen by as many goals as possible and hope that Churchill Brothers defeat Mahindra United.
Mohammad Rafi's fourth-minute strike from an Edeh Chidi pass was cancelled out in the added time of the first half by Mumbai FC's Felix Abogye. The Nigerian scored from the spot after D Ravanan tackled K Aseem from behind.
Mumbai FC, who lost 1-3 to Churchill Brothers in their first match, must be grateful to goalkeeper Kalyan Choubey for keeping their hopes alive of a semi-final berth.
He made at least four crucial saves, blocking Sukhwinder Singh and Douhou Pierre's longrange efforts. Mahindra United also had two of their goals disallowed due to offside.
Mahindra United dominated from the start, with Pierre orchestrating the moves down the middle. Paresh Shivalkar and Rafi were constantly switching positions on both flanks, keeping the opposition on tenterhooks.
Perhaps done in by the heat, Mahindra United's tempo subsided after the breather. They still held sway but failed to find the winner.
Pereira's boys though were guilty of wasting the set pieces. They earned 10 corners on either side of the break but could not convert any of them. "We have to work on them," admitted Pereira.
Too much dependence on Okolie Odafe saw Churchill Brothers' attacks getting stifled. Army XI kept the last I-League's top-scorer under a tight leash and barring a booming right-footer from the free-kick in the second half that crashed onto to the woodwork, Odafe was largely ineffective.
In fact, Army XI came out stronger towards the later stages of the match but Thirunavakarasu's effort went wide and Mahesh Rai's shot went straight to goalkeeper Arindam Bhattacharya.
Army XI, following their 0-3 drubbing to Mahindra United, played more organised football. They guarded their defence in numbers and had they been a bit more adventurous, could have even come out with a positive result.