NAGPUR: India's left-arm paceman Zaheer Khan picked two wickets in successive overs to rock South Africa early on the opening day of the first Test on Saturday.

Zaheer (2-15) sent back openers Ashwell Prince and Graeme Smith in a fiery opening spell before the tourists reached 90-2 at lunch at the Vidarbha Cricket Association stadium in Nagpur.

Jacques Kallis was batting on 55 with Hashim Amla (24 not out) at the break.

The South Africans started out tentatively after captain Smith won the toss and elected to bat on what appeared a slow wicket.

Prince was out for a duck, caught behind by wicketkeeper Mahendra Singh Dhoni in the fourth over when he failed to fend off a bouncer from Zaheer.

The pacer struck again in his next over to remove Smith (six) with a ball that moved through the bat and pad gap, cleaning up the stumps in spectacular fashion.

Reduced to a shaky 6-2, Kallis and Amla then steadied the innings with some resolute batting, putting on 84 runs for the unbroken third wicket.

Kallis looked confident against the spinners, slog-sweeping Harbhajan Singh twice for a huge six and a four in an over to race to his 53rd Test half-century.

India earlier handed Test caps to Subramaniam Badrinath and Wriddhiman Saha for the crucial tie that set the ball rolling for the contest between the world's top two teams.

Saha, 25, came in only because Rohit Sharma, called in as cover for injured middle-order batsman Venkatsai Laxman, hurt his left ankle during warm-up before the toss.

South Africa went in with a three-pronged pace attack spearheaded by Dale Steyn and a lone specialist spinner in Paul Harris.

The second and final Test begins in Kolkata on February 14.