Former captain Sourav Ganguly feels that the on-field verbal exchange between Virat Kohli and Ben Hilfenhaus in the fourth and final Test between India and Australia is part and parcel of international cricket and signifies "competitive spirit".

Young India batsman Kohli, who notched his maiden Test hundred on Thursday, was involved in a heated exchange with Australian fielders on the third day, and Ganguly said such incidents happen and should be left on the cricket field.

"There has been a lot of talk and reports about the exchange of words between Virat Kohli and Ben Hilfenhaus towards the close of play on Thursday. The boys in the middle fight hard and these sort of situations do happen on a cricket field -- and should be left in the middle," Ganguly wrote in his column for Sydney Morning Herald.

"The exchanges also signify the competitive spirit with which the game is played and that should never be taken away. Sport is always competitive and that's what people come to watch. They love the competition on the field and that is why they keep coming back to watch the champions," he said.

"One must also remember that off the field there is tremendous respect between the two teams and that's how it should be," he added.

Ganguly praised former pacer Craig McDermott for his role in training the young Australian fast bowlers during the Test series.

"Craig McDermott's role has been a very valuable one in helping Australia set up a series victory over India this summer. I saw McDermott bowl in 1991 when I toured this country as a 17-year-old. He would bowl such outstanding lengths and he has managed to get those young quicks bowling to such lines," Ganguly wrote.

"They have gained immensely from the lengths they have bowled and it's been very clever tactics from them. India has lost wickets at regular intervals and a lot of credit needs to be given to the Australian bowlers for toiling hard once again on a good surface," he said.

"The pressure they have put on the batting, with consistent length and line at good pace, is something to be really applauded -- and for a lot of young bowlers to learn from around the world," he added.