Wellington: A lead of over 600 runs and five sessions of bowling would be enough to clinch the third Test and the series against New Zealand, in-form Indian opener Gautam Gambhir said on Sunday.

"If we can set New Zealand over 600 runs they will be out of this match and will only play to survive rather than win," he said after third day's play.

"We have got two days and the kind of bowling we have we can easily bowl them out in five sessions. If we can't do that, then we don't deserve to win," added Gambhir.

India have not won a series in New Zealand since 1968.

The pugnacious left-hander, who struck a fluent 257-ball 167 in the second innings to help India take a mammoth 531-run lead, rated the match-saving marathon 137 in the second Test in Napier as the best ton in his 25-Test-old career.

"The most satisfying century in my career was at Napier because we had to play out two-and-a-half days which is always tough in any condition, even if the wicket is flat. It is hard to play seven sessions. That was very satisfying and gave me a lot of confidence coming into this game," he said.

He was, however, disappointed that he could not convert the 167 at Basin Reserve into a double hundred.

"It would have been very special to get a double hundred in New Zealand. The way I was hitting the ball and seeing it, I could have achieved it. But I played a bad shot. It is very disappointing," said the 27-year-old.

"As everyone says when things are going your way you should try and make it count as much as possible. I believe in that because you never know when bad form is round the corner," he said.

Asked how he build the tempo of his innings, Gambhir said, "We lost Sachin, so I had to build a partnership with VVS Laxman which was very important from the team's point of view. As we wanted to play New Zealand out of this Test match, it was very important for us to have partnerships. That is why I changed gears."

Gambhir has now aggregated 445 runs in the series, including two successive hundreds with an impressive average of 89, and he is satisfied that he was going great guns in New Zealand.

"I remember when I got my 150 in a ODI in Sri Lanka, I was asked how challenging it would be in New Zealand as an opening batsman. It was a big challenge for me on my first foreign tour away from the sub-continent. But it is satisfying that I have made myself count."

He said the away series against Sri Lanka in August last year changed his fortunes.

"My comeback in Sri Lanka was the turning point in my career. Scoring runs against (Ajnatha) Mendis, (Muttiah) Muralitharan and (Chaminda) Vaas gave me a lot of confidence.

Getting a double hundred against Australia in Delhi was a very big moment. I haven't looked back since then," he said. He added a batsman can play his natural game when he has a secured place in the team.

"When you don't have secured slot in the side, you would hesitate to play your natural game. But once you start feeling secure, you could play your natural game and enjoy yourself."