The left-handed opener struck 126 not out with 16 fours off 117 balls at the Reliance Stadium as India ended at 229-1 in reply to New Zealand's 224-9.

India reached its target with more than 10 overs to spare and took an unassailable 3-0 lead in the five-match series.

It was the second consecutive ton and ninth overall in one-day matches for Gambhir, who also scored an unbeaten 138 in the second ODI at Jaipur.

Gambhir dominated from early on and comfortably hit boundaries on either side of the wicket with quick use of his feet as India reached the 100-run mark by the 15th over.

Gambhir added 115 with opening partner Murali Vijay, who made a slower 30 off 50 deliveries before he was run out to a direct hit from Kiwi skipper Daniel Vettori. Virat Kohli (63 not out) then kept Gambhir company to ensure a one-sided end.

“This was an important game because we wanted to seal the series,” man of the match Gambhir said. “Our bowlers did a good job containing the opposition to such a low score.” Gambhir, leading the side in the absence of several senior players including regular skipper Mahendra Singh Dhoni, ensured India kept the momentum against an opposition which failed to lift its spirits ahead of the World Cup, which starts in February.

It was the ninth consecutive loss in one-dayers for New Zealand. The visitors' last win was against India in a tri-series match at Dambulla, Sri Lanka, in August. The run of losses includes a shock 4-0 defeat against Bangladesh in a five-match series that preceded the tour to India.

Earlier, it took a gritty 72 not out by James Franklin to lift New Zealand to 224-9.

The left-hander added 94 runs for the eighth wicket with Nathan McCullum, who scored a brisk 43.

Franklin faced 108 deliveries, hitting five fours and a six, and helped to salvage some pride after New Zealand had been reduced to 107-7 on being asked to bat first.

Zaheer Khan, Ravichandran Ashwin and Yusuf Pathan claimed two wickets each for the home side, which continued its domination after winning the opening two matches of the series with ease.

The Indian pace attack, led by Khan, justified Gambhir's decision to bowl first to take advantage of early morning conditions.

Khan removed Brendon McCullum without scoring as the batsman edged a good-length delivery to Vijay at second slip. The left-armer then had Ross Taylor caught behind off an inside edge for 4.

In between, Gambhir's direct hit from mid-on ensured the departure of Martin Guptill for 12 after the opener hit Khan for a superb six over mid-wicket.

New Zealand continued to struggle as first-change bowler Munaf Patel trapped Kane Williamson after the youngster had made a slow 21 off 50 balls, then off-spinner Ashwin had Scott Styris caught by Yuvraj Singh at leg slip for 22.

Pathan produced a twin strike before Franklin and Nathan McCullum came together to repair the damage.

“It was tough for our bowlers once the wicket had dried,” Vettori said. “We could have put up a fight if we had scored 240 or 250 but the Indian top order has been too good.” India won the first match at Guwahati by 40 runs and the second at Jaipur by eight wickets.