The eagerly-awaited clash between East Bengal and Mohun Bagan ended in a 1-1 draw at the near-packed Yuba Bharati Krirangan in Kolkata on Sunday.
On Sunday, the encounter was marred by widespread clashes that broke out in the stands and missiles were fired as referee flashed two red cards and nine yellow cards.
East Bengal went ahead in the 10th minute when Sanju Pradhan converted a penalty, but Jose Ramirez Barreto headed home beautifully in the 29th minute to bring the match on an even keel as both teams were locked 1-1 at half-time.
If both the teams showed spirited fight in the first-half, the second half turned ugly as Bagan resorted to rough play while East Bengal too retaliated.
East Bengal were reduced to 10 men after Gurwinder Singh picked his second yellow in the 70th minute.
Mohun Bagan were also reduced to 10 players in the 93rd minute when Ashim Biswas stamped on Mehtab Hussain that provoked East Bengal coach Trevor James Morgan to cross the white line and join in the clash in a fit of rage as the series of ugly clashes stretched the second-half by more than 11 minutes.
Having already scripted three wins against their bitter rival this season, East Bengal got a superb start, even as Mohun Bagan under technical director Subhas Bhowmick did not seem bogged down in the high-voltage clash.
Surkumar Singh's hand ball inside the box proved costly for Mohun Bagan who conceded a 10th minute goal after Sanju easily converted from the penalty.
But the full strength Mohun Bagan, studded with national players Surkumar, Deepak Mondal, Anwar Ali, N Mohan Raj and Rakesh Masih, put East Bengal under pressure early on.
In the fourth minute, East Bengal custodian Sandip Nandy thwarted a nice attempt by Surkumar as the table leaders had a lucky escape early on.
In the absence of suspended Robin Singh, East Bengal's in-form forward line-up found it difficult to settle down.
East Bengal's leading goal scorer Tolgay Ozbey was impressive, but the Australian star striker did not find enough assistance from Sushil Singh who was brought in place of Robin.
Ozbey brilliantly set it up in the sixth minute, but Sushil failed to utilise the ball as East Bengal had to wait for to take the lead.
In an eighth-minute move, a surging Ozbey crossed it for Sushil from the right, but to Mohun Bagan's agony it found Surkumar's hand inside the box as referee Pratap Singh did not have any hesitation awarding the penalty in favour of East Bengal.
Without much fuss, Sanju gave East Bengal the lead as Mohun Bagan goalkeeper Shilton Paul wrongly judged the shot.
But Barreto brought Mohun Bagan back into the game displaying his old and silken touch with a superb header in the 29th minute.
Capitalising on a Surkumar cross from the right, Barreto nodded in an angular header that screamed past East Bengal goalkeeper Sandeep Nandy while their defence was clueless.
Stepping up the attack, Mohun Bagan once again created an opportunity in the 35th minute, but Nandy averted the danger denying a surging Ishfaq Ahmed from the left side of the box.
Mohun Bagan had a chance to take the lead, but Barreto failed to score from a lovely cross by Edeh Chidi as both teams were locked 1-1 at half-time.
The second-half was full of clashes and players engaging in a scuffle as both the teams failed to score to settle for a draw.
East Bengal's weak attack in absence of Robin Singh was badly exposed in the second-half as Sushil's lack of co-ordination with the in-form Ozbey proved dear for the table leaders.
Sushil suandered a glorious chance from Ozbey in the 49th minute.
In the dying moments, East Bengal had some fine chances but they failed to score.
Unbeaten in the league so far, East Bengal now have 31 points, while Mohun Bagan have 19 points at the halfway stage.