Mohun Bagan unleashed an attacking brand of football to overwhelm Oil and Natural Gas Corporation 5-1 in their opening Group II quarter-final league match of the 122nd ONGC [Get Quote] Durand Cup at the Ambedkar Stadium on Wednesday.

Surkumar Singh (ninth minute and 90+2) and Nigerian Chidi Edeh (16th and 77th) struck twice while Jose Barretto (43rd) scored once for the Kolkata [Images] giants, while Chukwuma Udofia pulled one back for ONGC in the 82nd minute.

Mohun Bagan, who finished runners-up in the IFA Shield last week in Kolkata, now need just a draw against JCT in their last quarter-final league match on Friday to make it to the semi-finals as Group II toppers.

ONGC are out of the tournament, having lost their opening match to JCT 0-1.

Bagan coach Karim Bencherifa experimented with India defender Surkumar in the first half by putting him in between the backline and mid-fielders instead of his usual right back position.

The Manipuri made several runs into the ONGC defence especially from the right and set up forwards Chidi and Barretto on a couple of occasions though he was brought back into his normal right back position in the second session.

It was Surkumar, who opened the account for Mohun Bagan as his feeble right footer bounced awkwardly and hit the net after kissing the right post as the ONGC goalkeeper failed to judge the ball. Seven minutes later, ONGC paid the price for keeping the ball inside their box for too long as Chidi shot home following a scramble inside the penalty area.

Two minutes before the breather, Barretto made amends for wasting a penalty in the 19th minute, by firing in a right footer after being nicely set up by a deflection from ONGC defender CS Saleel from a long kick by goalkeeper Sangram Mukherjee.

The second half saw close contest between the two sides with ONGC making some raids in the Bagan citadel. Three minutes into the second session, J Lalsangjuala was clear at the left top edge of the box but he shot straight into the goalkeeper with Surkumar closing on him.

Mohun Bagan were denied another goal by the woodwork at the hour mark when a Chidi shot, after Barretto did all the spadework, came back to play after hitting the left upright.

Chidi though completed his double as he turned in a low right footer past the ONGC goalkeeper in the 77th minute, Surkumar completed the tally by firing in a 35-yard long ranger in the injury time.

• Complete football coverage