ATK Mohun Bagan beat East Bengal 2-0 at the Salt Lake Stadium in Kolkata when the fiercest rivals faced off for 383rd time in their history. Second-half goals from Hugo Boumous and Manvir Singh sealed the deal for the Mariners after a goalless first half.
Vishal Kaith faced an early test when Semboi's header was parried away nicely for a corner in the 17th minute.
Tempers then flared as both sets of players got involved in a couple of tussles before the half-time interval.
Kamaljit's mistake helped ATK Mohun Bagan claim the lead. Hugo Boumous' shot straight at the goalkeeper, but Kamaljit's failure to keep hold of the ball resulted in the opener. Manvir rounded off a great display with a ferocious strike from the right wing to double the lead.
Tuhin Das came the closest to scoring for East Bengal when his shot from outside the penalty box was parried away to safety by Vishal Kaith.
Here's a look at the player ratings after ATK Mohun Bagan clinched their seventh straight derby win.
ATK Mohun Bagan player ratings
Vishal Kaith - 7/10: The ATK Mohun Bagan goalie made a sharp reflexive save in the first half, but was left with little to do after that.
Subhashish Bose - 7/10: Subhashish Bose was tasked to keep Suhail quiet throughout the game and he did that to perfection. His first-half shot also came close to hitting the back of the net. His defensive and attacking contributions were crucial in ATK's victory.
Brendan Hamill - 7.5/10: Apart from the early chance to Semboi, ATK Mohun Bagan's backline, shepherded by Hamill, limited East Bengal's forwards. He negated Cleiton Silva's threats with his aerial presence and physicality.
Pritam Kotal - 7/10: Just like Hamill, Pritam had an equally dominant game. Although he was beaten in a couple of challenges, his calm presence at the back made a difference for the hosts.
Asish Rai - 7.5/10: Asish Rai, operating at right-back, was galloping up and down the pitch throughout the game. His ability to carry the ball was pivotal in keeping the flow of the match going.
Deepak Tangri - 7/10: Yet another solid display from Deepak Tangri. The young India international was winning duels in the middle for fun and kept recycling the ball.
Joni Kauko - 7/10: Kauko was a dominant presence in the middle of the park for Juan Ferrando's side. The Finland international won a number of tackles and his discipline thwarted the threat by East Bengal.
Hugo Boumous - 8.5/10: A man for big occasions, Huge Boumous marked the derby with a goal. The attacking midfielder's shot which produced an awkward bounce before Kamaljit Singh resulted in a goal.
Manvir Singh - 8/10: Manvir's hardworking performance was rewarded with a goal. Even though he struggled to create chances, his well-taken goal made a huge difference in the derby.
Liston Colaco - 7/10: Liston Colaco had a chance to assist a couple of goals, but poor decision making resulted in him ending up with nothing. He was penetrating the opposition's backline, but struggled to convert them. The young Indian winger's display is certainly worth praising.
Dimitri Petratos - 6.5/10: Petratos did not have a great game, but his off-the-ball running put pressure on the East Bengal defenders.
Lenny Rodrigues - 7/10: When ATK Mohun Bagan were leading by a goal, Lenny made a last-ditch interception to thwart the attack. His presence made an immediate impact.
Ashique Kuruniyan - 6.5/10: Ashique was tasked with closing down opponents and putting them under pressure.
Florentin Pogba - N/A: He came on late in the game and did not have much to do.
Carl McHugh - N/A: He replaced Hugo Boumous during the closing stages of the game.
East Bengal player ratings
Kamaljit Singh - 4/10: Kamaljit was at fault for both goals today. His poor judgment cost him on both occasions. He did not look convincing otherwise and struggled aerially as well.
Sarthak Golui - 5/10: Liston continuously tormented Sarthak by penetrating East Bengal's defense. He struggled to keep up and was caught out of position on numerous occasions.
Chungnunga Lal - 5.5/10: Chungnunga Lal was often dragged out of his position and was the second to most of the challenges.
Ivan Gonzalez - 5.5/10: Ivan Gonzalez's poor start to the season continued with yet another disappointing display. Just like Lal, his positional play was not at its finest.
Jerry Lalrinzuala - 6/10: Jerry begun the game well by stowing in a few threatening crosses, but lost his influence on the game as it progressed. He struggled to keep up with the pace of Asish Rai.
Charalambos Kyriakou - 7/10: Kyriakou was arguably East Bengal's best player on the night. He was consistently running up and down the field to make things happen but had no support.
Jordan O'Doherty - 6/10: Doherty was at the end of a penalty claim in the first half, but his display was substandard. He was beaten by Hugo Boumous comprehensively on numerous occasions.
V.P.Suhair - 5.5/10: Suhair had no influence on the game and failed to overcome Subhashish at left-back.
Mahesh Singh - 7/10: Perhaps the second brightest spot for Stephen Constantine and Co., Mahesh created a couple of clear-cut chances that went abegging in the first half.
Cleiton Silva - 6/10: East Bengal were not able to bring Cleiton Silva into the game. The former Bengaluru FC attacker was starved off service for the entire game.
Thongkhosiem Haokip: Semboi made a meaningful contribution by winning a header in the first half. His firm header forced Vishal Kaith to get down and make a huge save.
Eliandro - 6/10: Eliandro was brought on to get East Bengal into the game. However, he failed to do that.
Souvik Chakrabarti - 6/10: Often a tireless runner, Souvik made a few crucial interceptions and made things happen once he came on.
Aniket Jadhav - 5.5/10: Aniket was brought on for Suhair and failed to make any impact.
Tuhin Das - 7/10: Tuhin Das nearly scored in the closing stages of the game with a firm shot from outside the penalty box.
Alex Lima - N/A: He came on during the dying minutes of the match.