Jadeja takes 5-33 as SA subside to 83 all out in run-chase
Kohli, on his 35th birthday, equals Tendulkar's record for most ODI centuries (49)
India post 326-5 - Shreyas adds 77 to Kohli's ton
Rohit hammers 24-ball 40 to get India off to flier
India won toss and bat first in Kolkata
India likely to top group following victory
Deep Dasgupta
Former India wicketkeeper on BBC Test Match Special
That was a very poor delivery. A half tracker, Iyer didn't really have to do anything. Slowly bowled, he did well to hold onto his shape rather than get through the shot early.
A slog sweep from Virat Kohli off Aiden Markram seems destined for the boundary but a brilliant dive out on the boundary from Heinrich Klaasen saves three runs.
Markram's next ball is a little short and Kohli rocks back and heaves it through mid-wicket for four.
Final ball of the over and Markram holds the ball back, but it gives Shreyas Iyer all the time in the world to hammer the South African spinner into the stands for six.
India are putting their foot on the gas again.
Left-arm seamer Marco Jansen, a tall imposing figure, has returned to the attack with some disciplined lines.
Just three runs off it as Shreyas Iyer and Virat Kohli middle a few into the offside, but can only pick out the fielders in the deep.
What will India be happy with here? 380, 390?
A quick bit of liquid refreshment for the players.
Shreyas Iyer got to his half-century in style. Even an appreciable tap of the bat from Virat Kohli at the other end.
Deep Dasgupta
Former India wicketkeeper on BBC Test Match Special
In the last few days there's been a fair bit of dew at Eden Gardens. But it's been overcast today, so you might not get so much and the pitch might settle under lights.
Aiden Markram into the attack for South Africa attempting to put the brakes on this India juggernaut.
Quite a tidy start from the part-time off-spinner as Shreyas Iyer and Virat Kohli flick and nudge the ball into the gaps.
A single apiece for Shreyas Iyer and Virat Kohli, plus a wide, from the over as the floodlights start to take over from the natural light at Eden Gardens.
Image source, ReutersThanks, Tom.
Ominous signs that Virat Kohli is on for a big one here.
Shreyas Iyer, too, for that matter.
Shreyas Iyer's eyes light up as Marco Jansen bowls full and wide, with Iyer smashing the ball through the covers for another boundary.
Then next four is even better. Jansen goes short and Iyer dismissively swats it away cross-batted to the rope.
14 runs off the over in total. The return to seam has transformed the atmosphere - Eden Gardens is bouncing now.
On that note, it is time for me to take a break. Here is Timothy Abraham to guide you through the rest of the India innings.
With Keshav Maharaj bowled out South Africa turn back to Marco Jansen.
His second ball is carted through the covers by Shreyas Iyer to bring up his half-century.
He is in the mood.
#bbccricket
Kohli does create a sense of theatre. It’s not all in his strokeplay - it’s the interplay between himself and the opposition, interactions with the umpire, and the ever-knowing feel for the crowd’s mood. He's something else.
Gray Proud, from Cambridge
Calm as you like from Shreyas Iyer. All about timing and technique.
This could be the answer to the second question.
Tabraiz Shamsi drags one down and Shreyas Iyer absolutely pummels it to the rope.
A straight drive nearly brings another four but for some smart fielding Marco Jansen, who flicks the ball back just in time to save his side two runs.
Keshav Maharaj is bowled out, ending with excellent figures of 1-30.
Will we see the return of seam next up? Is this the signal for India to put the foot on the accelerator?
Questions, questions.
And there it is.
Another huge road from the raucous crowd as Virat Kohli pushes the ball into the off side for a single to reach his half-century.
Not his most explosive, but brilliantly played given the circumstances.
Is this the day he goes level with the great Sachin with a 49th ODI century?
Deep Dasgupta
Former India wicketkeeper on BBC Test Match Special
Maharaj has only one left. Sooner or later they will have to get the seamers on.
Eden Gardens comes alive - not for Virat's 50, but for another huge six from Shreyas Iyer as he smashes the ball over mid-off and into the crowd.
South Africa will be wishing Keshav Maharaj could bowl more than allotted 10, he is 1-23 from his nine overs so far. Excellent stuff.
Two singles come from his latest over, with Virat Kohli moving on to 48.
Firdose Moonda
Cricinfo writer on BBC Test Match Special
I'm interested to see what happens when Maharaj completes his 10. Aiden Markram might get a bowl with his off-breaks.
The floodlights have kicked into action as the natural light begins to fade at Eden Gardens.
India are showing signs of stepping things up as they push a couple of shorter deliveries from Tabraiz Shamsi to the square leg boundary for a pair of twos.
Eight runs come off the over in total, which is the most expensive since the final over of the powerplay.
Firdose Moonda
Cricinfo writer on BBC Test Match Special
I don't think Keshav Maharaj has turned the ball this much in his career.