For the last several years, Team India was used to seeing Sachin Tendulkar walk out to the middle at the fall of the second wicket in Tests. However, with the Master Blaster's retirement, Kohli was the chosen one for that spot. And in his first day in that new role, he impressed one and all with his fifth Test century.
Thanks to the right-hander's career best 119 (181 balls, 18x4), India ended the first day at a satisfactory 255/5 in 90 overs. Ajinkya Rahane, playing his second Test, also stood out with an unbeaten 43. At stumps, Rahane was with captain MS Dhoni (17 not out).
Kohli stole the thunder on the first day as he displayed wonderful counter-attacking ability with dazzling array of strokes all round the wicket after openers Shikhar Dhawan (13) and Murali Vijay (6) were dismissed cheaply by Dale Steyn (1/56) and Morne Morkel (1/27) within 15.1 overs.
Kohli, India's premier batsman, hit 18 sweetly timed boundaries in his 181-ball knock with the standout shot being a pull off the fast and furious Steyn. He played some flowing drives, played the square cut well and was severe on leg-spinner Imran Tahir, who was repeatedly pulled towards the deep mid-wicket boundary.
His shot selection was admirable as he was ready to leave a lot of deliveries but didn't forget to punish the loose balls. Kohli reached his fifth Test hundred when he played off-break bowler JP Duminy's delivery towards mid-wicket for a couple before celebrating the milestone with a leap and punch of his fists in the air.
At tea, India 164/4
Kohli was in sight of a century as India added 94 runs for the loss of two wickets in the second session of play.
At the tea interval, the visitors were 164/4 in 55 overs. Kohli was impressive on 84 not out while Ajinkya Rahane kept him company with 12.
Between lunch and tea, India lost Cheteshwar Pujara and Rohit Sharma. Pujara was run out for 25 while with five minutes for the break, Rohit played a poor shot to head back to the pavilion for 14 runs.
Kohli, playing a Test in South Africa for the first time, looked in good nick. He continued his good work from the first session to head towards a ton.
The right-handed youngster has 14 boundaries in 113-ball knock. Rahane struck three fours.
At lunch, India 70/2
After the early loss of openers, Cheteshwar Pujara and Virat Kohli steadied the innings as India reached 70/2 at lunch.
Kohli was unbeaten on 32 while Pujara was 18 not out after 27 overs of play.
Kohli and Pujara have so far added 46 runs for the third wicket after India were in trouble at 24/2 in 15.1 overs.
Kohli, hit five boundaries while Pujara had two in his 61-ball knock. Kohli has been positive in his 32-ball stint in the first session.
India openers Murali Vijay and Shikhar Dhawan played cautiously to see of the first half hour but the latter fell to a poor shot in the ninth over.
Having moved to 13 off 27, Dhawan attempted a pull shot off Dale Steyn and was caught by Imran Tahir. It was an unnecessary shot by the left-hander.
Vijay batted 69 minutes and faced 42 balls for his 6 before being scalped by first-change bowler Morne Morkel.
The right-hander found it hard against Morkel, who bowled 11 balls at Vijay and did not concede a run. Finally, he got his reward as Vijay edged the ball to wicketkeeper AB de Villiers.
Vijay could have been dismissed a few balls earlier if not for a tough chance grassed by Hashim Amla at shortleg off Morkel.
Morkel was introduced by captain Graeme Smith in the 12th over. Immediately, he beat the bat of Vijay few times.
The hosts started the bowling with Steyn and Vernon Philander. Jacques Kallis too have pressed into action in the first session of play. By far, Morkel was the best of the lot, with figures of 6-4-6-1.
India captain MS Dhoni won the toss and elected to bat.
India went in with three fast bowlers (Zaheer Khan, Mohammed Shami and Ishant Sharma) and one spinner - R Ashwin. Ajinkya Rahane will bat at number six, Dhoni said at the toss.
Dhoni broke Sourav Ganguly's record for most Tests as India captain. Today's Test is Dhoni's 50th as India skipper.
This is the first Test match for India since the retirement of Tendulkar. The Master Blaster bid adieu to cricket last month after playing 200 Tests.