Unbeaten IOCL finished their pool A engagements with 12 points while Indian Overseas Bank with nine points, joined them in the knock-out stage.
IOCL need to thank their international stars Deepak Thakur and penalty corner specialist Raghunath who scored twice each while Roshan Minz and Prabhjot Singh also got into the act.
Army XI, who needed to win, scored through Chanan Aind (2) and Benoy Bhengra. The team finished third in the pool with six points.
Meanwhile, last year's joint winners Air India kept themselves in the running for a semi-final berth with an unconvincing 2-1 win over Punjab National Bank for their second win in pool B matches.
Air India and Bharat Petroleum, both with six points, meet in their concluding league fixture.
Punjab National Bank finished on nine points, and despite Wednesday's defeat, are certain to qualify for the knock-out phase.
In a tight match, Air India took a 2-0 lead when former India forward Shivendra Singh struck in the sixth minute and Somanna Pradhan sounded the boards in the 23rd. PNB fought hard in the second-half, but could only reduce the margin through Ajitesh Roy in the 65th minute.
Earlier, in an inconsequential pool B match, Indian Bank edged out SAIL, Rourkela, 7-6 as both completed their league engagements on three points. The bankmen finished last on inferior goal difference.
Former international V. Raja with four goals spearheaded Indian Bank's victory while Pilip Martin, Umesh and E. Charles contributed to the tally.
For SAIL, Deepak Kullu topped with three goals with Rajin Kandulna, Sunil Toppo and David Dung Dung added one each.
--IANS (Posted on 19-09-2013)