The fan came to Rohit Sharma, who was standing at the slips, and touched the opener's feet. The incident happened when Vernon Philander had just walked in after the dismissal of Senuran Muthusamy.
The incident drew an angry reaction from Gavaskar, who was in the commentary panel at the time. "These incidents happen because security people are not watching the crowd but are watching the match. This has been the perennial problem in India. The security is not there to watch the match for free. They are there to stop such interruptions from happening," he said.
"I say put the camera on the security and check whether they are watching the match or the crowd. This is a dangerous security issue which is what you are there for, to make sure no one goes into the ground. Anyone can cause damage to a player. It has happened in the past, why take a chance," Gavaskar added.
It was the third such incident in the ongoing South Africa tour of India. In the first Test at Vizag, a fan shook India skipper Virat Kohli's hand and tried to take a selfie with the on-field cricketers.
Earlier during the 2nd T20I between the two teams in Mohali, the proceedings were interrupted twice as fans entered the field.
( With inputs from IANS )