Meanwhile, former skipper Rahul Dravid has dropped out of top 20 for the first time in 11 years in the ICC Player Rankings for Test batsmen. Pushed down by eight places, Dravid is now placed at 26th position.
Gambhir, who scored 206 and 36 in the drawn third Test at New Delhi, jumped 11 places to 18th position. He had started the series at 37th position, but has climbed 18 places after three Tests in which he has scored 463 runs.
Man of the Match of the Delhi Test VVS Laxman, who scored 200 not out and 59 not out, has jumped five places to 11th with a place in the top 10 now firmly within his sights, said a press release of the ICC on Monday.
Dravid's Sydney dismissal was wrong: Gilly
Dravid has lost 10 places since the start of the series in which he has scored 117 runs.
Opener Virender Sehwag has also lost ground after a disappointing Test and has dropped three places to 13th. Sachin Tendulkar has retained his 19th position but Saurav Ganguly has slipped one place to 24th spot.
Among the Aussies, opener Matthew Hayden returned to the top 10 after knocks of 83 and 16 not out. The Queenslander climbed two places to ninth position. However, Mike Hussey, who took over the number-one tag from the West Indies" Shivnarine Chanderpaul after the first Test in Bangalore, has slipped one more place to fourth while Michael Clarke has also dropped one position to 14th.