Chennaiyin raced to a three-goal lead in the first half, but the Blasters incredibly fought back in the second half before the away side put it beyond them once again.
Chennaiyin were buoyed by a brace by Rafael Crivellaro (39', 45') and a Nerijus Valskis' (45') strike right at the stroke of half time. But a hat-trick by Bartholomew Ogbeche (48', 65', 76'), the first of the season, threatened to bring Kerala Blasters back into the match. However, a brace from Chhangte (59' 80') and another Valskis goal (90') sealed the result for the away side.
The victory sees Chennaiyin climb to fifth spot, just two behind fourth-placed Odisha, while Kerala Blasters' hopes of finishing in the top four virtually ended, with them placed eighth now.
Though Kerala started the first half well, they could not fashion any real opening. Chennaiyin too were a bit passive as the match was locked down in the midfield. However, Chennaiyin came to life in spectacular fashion just as the first half was drawing to a close.
In the 39th minute, Chennaiyin took the lead after Kerala goalkeeper TP Rehenesh passed the ball straight to Crivellaro who sweetly tucked it home.
Things got worse for Kerala in the 45th minute when Valskis combined beautifully with Crivellaro before receiving the return pass and lashed a finish home. A minute later, Kerala were caught napping again. Anirudh Thapa sent a through ball forward for Valskis who was offside. But the Lithuanian did not interfere with play and Crivellaro took advantage, surged towards goal and finished with aplomb to make it 3-0 in no time.
The setbacks sparked a reaction from Kerala in the second half with Ogbeche leading them. Three minutes into the half, the Nigerian got on the end of a hopeful cross into the box from Jessel Carneiro and turned it in past goalkeeper Vishal Kaith.
However, Chennaiyin restored their advantage after yet another howler from the Kerala defence. Abdul Hakku's intended pass for Rehenesh was intercepted by Valskis who set up Chhangte who arrowed it past the Kerala goalkeeper.
Ogbeche had other ideas and scored a quickfire brace to make it 4-3. In the 65th minute, he beat Kaith with a clinical shot from outside the box before heading in Halicharan Narzary's cross in the 76th minute.
Just when one thought Chennaiyin had lost the plot, Chhangte settled their nerves with a fine strike from range in the 80th minute before Valskis helped himself to a second goal late on to seal a goal glut.
( With inputs from IANS )