India endured an eventful and injury-hit first session on Day 2 of the opening Test against South Africa, with skipper Shubman Gill retiring hurt due to a neck sprain and key wickets falling at regular intervals before the visitors reached 138 for 4 at lunch.

India remained 22 runs short of South Africa’s first-innings total of 159 when play broke for lunch.

The biggest setback came when captain Shubman Gill suffered a neck sprain while attempting a slog sweep off Simon Harmer.

Gill managed to strike Harmer for a slog-swept four over backward square leg but appeared to experience a whiplash in the follow-through, immediately clutching the back of his neck.

After the physio attended to him, he walked off grimacing, having faced only three balls.

"Shubman Gill has a neck spasm and is being monitored by the BCCI medical team. A decision on his participation today will be taken as per his progress," BCCI said in a release.

Gill’s departure added to India’s troubles in what had already become a tricky session.

Earlier, KL Rahul (39 off 119) and Washington Sundar (29 off 82) put on a valuable 57-run stand on a difficult, crumbling surface.

Harmer broke the partnership with a classical off-spinner’s dismissal, drifting and turning the ball away to take Washington’s outside edge, with Aiden Markram completing the catch at slip.

Moments later, Rahul was also caught by Markram at first slip while trying to cut Keshav Maharaj.

Rishabh Pant (27) offered brief resistance, striking a few sixes, but was undone by a well-directed short ball from pacer Corbin Bosch.

India’s scorecard read 79 for 2 after 35 overs, but with two wickets down and Gill retired hurt, the innings briefly appeared three down in their reply to South Africa’s 159 all out. By lunch, the visitors had recovered to 138 for 4.

Brief Scores: South Africa 1st Innings: 159. India 1st Innings: 138/4 (KL Rahul 39, Washington Sundar 29, Rishabh Pant 27, Corbin Bosch 1/6, Keshav Maharaj 1/66, Simon Harmer 1/22).