Rowllin Borges' own goal (4') and Thoi Singh's brace (15', 32') were cancelled out by a quick-fire hat-trick by Ogbeche in the first-half (29', 37', 39'). Borges' strike (54') sealed the tie in favour of the visitors.
John Gregory dropped striker Jeje Lalpekhlua for Carlos Salom in the first-team lineup. Further changes included Thoi Singh for Gregory Nelson and Isaac Vanmalsawma in place of Germanpreet Singh.
Eelco Schattorie was forced to change his goalie after TP Rehenesh was retrospectively suspended for his misconduct in the match against ATK. Pawan Kumar was slotted in goal in the hope of a clean sheet on the occasion of a rare start for the player.
In a game that kept both team's goalkeepers busy, it was Chennaiyin who drew first blood. Isaac's corner-kick into the box met the head of Rowllin Borges who mistakenly guided the ball into his own net.
The defending champions looked like they found their rhythm with their moves up the field causing the NorthEast United backline plenty of trouble. A high line coupled with sloppy defensive organization let the hosts double their lead.
Lalrinzuala's ball over the defence fell to Isaac who ran into the box before picking out Thoi Singh's surging run through the centre. The forward got to the ball first ahead of an onrushing Pawan Kumar and made it 2-0.
Carlos Salom put the ball in the net twice midway through the first half but his celebrations were cut short on both instances due to offside calls by the linesman.
Despite a 2-0 lead, Chennaiyin did not look safe at the back. Federico Gallego's persistence to drive into the box with the ball caused Eli Sabia to panic. The Brazilian defender's failure to clear the loose ball in the box was punished by Bartholomew Ogbeche who rushed to the spot and struck the ball into the bottom right corner.
The Highlanders thought they were back in the game and then they weren't. Three minutes after Ogbeche scored, Chennaiyin made it 3-1 at the other end. Raphael Augusto's mazy run into the box had the NorthEast United defenders on high alert. But they were unable to prevent his cross into the centre and Thoi's messy finish went in on his second try.
Ogbeche brought out his inner-Didier Drogba to pull his team back into the game for the second time. Borges' mesmerising ball into the box took the entire defence out of the equation and the striker chested the ball before smashing it past Karanjit.
The former PSG striker completed his ten-minute hat-trick before the first half's close. It was a stinker for both Mailson Alves and Eli Sabia against Ogbeche. To add insult to injury, the hosts' midfield failed to tackle Gallego's artistry on the ball. The midfielder split the defence with a through-ball to release Ogbeche who skipped past Karanjit and passed the ball into the net to make it 3-3.
Chennaiyin tried to slow down the pace of the game and looked to keep hold of the ball after the restart. The visitors, however, were hungry for more.
Mailson Alves failed to clear Reagan's dangerous cross into the box from the right flank and the ball fell perfectly for Borges who made amends for his own goal with a strong finish into the net.
Andrea Orlandi's entry put an end to Mailson's terrible outing at the back. The likes of Jeje Lalpekhlua and Gregory Nelson were also brought on to force a change in momentum but Ogbeche's rapid-fire hat-trick had sucked the confidence out of the defending champions who were ultimately handed their third defeat on the trot.