The Kolkata-based team extended their lead in the second half when Garcia scored a few minutes into resumption.

Valskis pulled one back for his team with a strike in the 69th minute.

There was more to come as Hernandez scored ATK's third in the stoppage time, and that was the final nail in the coffin for Chennaiyin.

The two teams were brilliant in the play-offs with Chennaiyin getting the better of FC Goa in a thrilling two-legged tie that finished 6-5 on aggregates and ATK producing a second-leg turnaround to send defending champions Bengaluru FC packing with a 3-2 win on aggregate.

However, ATK had the last laugh, bagging an AFC Cup spot alongside a hat-trick of titles.

ATK claimed an unprecedented third Indian Super League (ISL) title triumph with a 3-1 victory over arch-rival Chennaiyin FC in a summit showdown that was played behind closed doors here on Saturday.

Javier Hernandez (10th and 90+3) and Edu Garcia (48th) scored for ATK, while Valskis found the net for Chennaiyin FC in the 69th minute at the Jawaharlal Nehru Stadium.

The final was held without spectators owing to the COVID-19 pandemic.

ATK led 1-0 in the first half, courtesy a goal from Hernandez with an assist from the in-form Roy Krishna.