Rohit Sharma has sealed the opener's slot with his third century of the South Africa series and will be India's game changer on away tours, Indian batting coach Vikram Rathour said Saturday.
Sharma hit an unbeaten 117 on the opening day of the third and final Test to lead the hosts to 224 for three when bad light followed by rain forced early stumps in Ranchi.
The senior batsman, who hit twin centuries in his debut as Test opener in the first match, put on 185 runs with Ajinkya Rahane, 83 not out, after India were in early trouble at 39-3.
"I always believed he is too good a player not to be playing in any format. It was a good call to make him to open," Rathour said of the limited-overs star.
"With the amount of runs he has scored, he has settled the issue (of opening the batting) for the time being.
"Somebody of his experience and the kind of cricket he plays, if he starts coming good top of the order, it changes everything for the Indian team, even when you're touring."
Virat Kohli's India will travel to New Zealand for a full series next year including two Tests in February-March.
Sharma, who is playing his 30th Test since his debut in 2013, curbed his attacking instincts to get through a fiery morning spell from South Africa's Kagiso Rabada who struck twice.
Anrich Nortje joined forces to earn his maiden Test scalp after trapping Indian skipper Virat Kohli lbw for 12.
Sharma played it cool to fifty then soon launched an attack with a barrage of sixes, reaching his sixth Test hundred with his fourth hit over the fence amid loud applause from the home crowd.
Rathour believes the experienced batsman has got his game plan together after settling in to the opener's role alongside Mayank Agarwal.
"He is such an experienced player. I don't think you need to change anything with his technique. The only adjustment I think he had to make was his gameplans," said Rathour.
"Once he's set, he's a phenomenal player, we all know that he can really punish you. So he just needed to make that mental adjustment to his gameplans. He has done that well."
Sharma made 176 and 127 in the first and second innings of the opening match to set the tone for India's domination in the series.
The 50-year-old Rathour, a former batsman who played six Tests for India between 1996-97, also praised Rahane's approach on a tough wicket.
Rahane, India's Test vice-captain, hit 11 fours and one sixes during his 135-ball stay at the wicket.
"Whenever he bats with this intent he looks really a good player. So today he showed that," said Rathour.