Sunil Chettri bagged a hat-trick while Bhutia Baichung also got on the scoresheet at Ambedkar Stadium as the hosts saw off the defending champions in impressive fashion.

The result also means India will now take part in Asia's showpiece event, being held in Qatar, for the first time sine 1984.

India quickly raced into a three-goal lead, although Chetti's ninth-minute opener was tinged with controversy as it was initially ruled out for offside before Uzbekistan referee Valentin Kovalenko changed his decision following consultation with Qatari linesman Mohammad Jaber Dharman.

Baihung doubled the lead after 18 minutes when he volleyed home Samir Naik's cross before a 30-yard cracker from Chetti made it 3-0 four minutes later.

That spurred Tajikistan into life and Fatkhuloev Fatkhullo pulled a goal back for Pulod Kodirov's men just before the break with a 20-yard volley.

They continued to press after the break but Subrata Pal proved a significant obstacle in the Indian goal before Chetti completed his treble in the 76th minute, pouncing on a loose ball that keeper Alisher Tuychiev allowed to escape from his grasp.

"Tonight was not about tactics or team plans but it was all about a team's desire to win," said India coach Bob Houghton.

"It was one of those performances which is the culmination of a lot of hard work. The boys have been together now for a long time. They've played a lot of matches and they trained very hard.

"They deserve the win. It was a good team effort and it there were some really good individual performances."

Tajikistan coach Kodirov felt his team never recovered from India's disputed first goal.

"Any team would be broken after such a goal," he said.

"The linesman had clearly signalled for offside and then the referee changed his mind. The referees are clearly to blame."