Defending champions East Bengal overcame a 0-2 deficit to hold Mohun Bagan and ensure that the battle for the Calcutta League goes down to the last three matches. Both teams are now on 20 points from eight games in the 12-team competition but Mohun Bagan are in pole position by virtue of having scored more goals, 18 to East Bengal’s 16. Johnny Acosta may have scored better goals in a long career for Costa Rica that includes two World Cup finals but his first for East Bengal handed them a lifeline when, in front of over 60,000 at the Salt Lake stadium here on Sunday, things seemed to be going south.Trailing 1-2, East Bengal emerged for the second half with a renewed sense of purpose. The equaliser took 15 minutes in coming, Laldanmawia Ralte neutralising Mohun Bagan’s goals from Pintu Mahata and Henry Kisseka that came in the first 30 minutes of the biggest match of this competition that is 120 years old.In his first match since Costa Rica’s World Cup campaign ended on June 27, Acosta looked circumspect and once allowed Mohun Bagan’s Dipanda Dicka a look on goal with an aimless shot from near the centre-line. But it was during set-pieces won by East Bengal that Acosta made his presence felt. The first ended in a foul on Mohun Bagan goalie Shilton Paul. The second had a header that wasn’t on target. It was different when East Bengal, trailing 0-2 and looking ragged, got another. Mahmoud Al Amna’s corner-kick travelled from left to right because Shilton Paul got a hand to it before Lalrindika Ralte, a 40th minute substitute for KP Singh Grewal that proved to be game-changing, swung it back in. Mohun Bagan central defender Eze Kingsley was ball-watching and it gave Acosta a chance to head from close. Paul blocked that but the ball ricocheted off Acosta into the goal. A brief raise of the hand was all that Acosta, 35, did to acknowledge the cheers from the other end of the stands in the season’s first Kolkata derby.East Bengal pressed more in the second half and looked like scoring when Mehtab Hossain’s first touch, after coming on in the 53rd minute, saw him pull up injured and put Amna in the clear. Paul denied Amna, easily the best player on the pitch. Mohun Bagan were struggling to get the ball out of their half and from a Lalrindika Ralte corner-kick ---- swinging into the near post off that dangerous left foot which has scored many impressive goals for East Bengal during an earlier stint --- that Paul parried, Laldanmawia Ralte stabbed home.Mohun Bagan’s goals came from right-back Arijit Bagui’s assists and stemmed from poor defending though Acosta wasn’t responsible for either. Mahata struck in the 19th when he and Kisseka were free inside the area because East Bengal’s midfielders didn’t track back.Mahata, the wide midfielder from Jangalmahal in West Bengal, is a Mohun Bagan product, having played for them in the nursery league before joining the club’s academy in Durgapur. Mahata joined the senior team last term but was hit by an illness. He was adjudged Man of the Match. Again left free inside the penalty box, Kisseka scored when central defender Mehtab Singh failed to close him down.