Mohammed Shami's hostile morning spell and an acrobatic catch by Wriddhiman Saha were the highlights of the first session as India reduced South Africa to 136 for six at lunch on the third day of the second Test, here on Saturday.

South Africa's most experienced pair of skipper Faf du Plessis (52 batting off 76 balls) and Quinton de Kock (31 off 48 balls) were trying to resurrect the innings with a quick stand of 75 runs but Ravichandran Ashwin (1/28 in 8 overs) removed the latter to make matters worse.

Shami (2/28 in 10 overs) bowled with a lot of fire during the session while Umesh Yadav's (3/27 in 8 overs) third wicket of the innings primarily belongs to Saha, who once again proved why he is rated as the best in the world.

On a pitch where Indian batsmen looked at ease, it was an every moment struggle for the Proteas batsmen.

Shami was getting the semi new-ball to dart back in after pitching while Yadav was primarily bowling outswingers.

Nightwatchman Anrich Nortje (4) was uncomfortable from the start as Virat Kohli set an attacking field that included four slips and a gully.

Shami got deliveries to rear up from the length and one such delivery was awkwardly fended by Nortje and skipper Kohli at fourth slip took a smart catch diving to his right.

Theunis de Bruyn (30) hit a couple of cover drives but it was a moment of inspiration from Saha that brought about his end.

Trying an expansive drive off Yadav, De Bruyn's hard flash was flying towards first slip and an aerial Saha plucked it off thin air leaving South Africa tottering at 53 for 5.

However, Du Plessis and De Kock batted positively punishing the loose balls and didn't look in much trouble like the earlier batsmen.

Du Plessis had nine hits to the fence including one maximum, while De Kock hit seven boundaries.

It was Ashwin, who removed De Kock with a classical off-break that pitched on the middle and the southpaw was squared up and beaten trying to play for the turn with bails clipped.