South Africa captain Faf du Plessis felt Kagiso Rabada was "extremely unlucky" to end up on the losing side in a six-wicket Cricket World Cup defeat to India.

The Proteas were missing quicks Dale Steyn and Lungi Ngidi through injury, but Rabada briefly threatened to turn the tide on his own.

Rabada, who had earlier cracked Shikhar Dhawan's bat, dismissed the opener to bring opposition captain Virat Kohli to the crease.

The South Africa paceman had earlier suggested Kohli was "immature" and a gripping spell saw him work over the batsman without reward.

Rabada ended up claiming 2-39 as Rohit Sharma made an unbeaten 122 in India's chase, leaving Du Plessis to rue his bowler's misfortune.

"[Rabada] was a champion today. He was extremely unlucky," the skipper said in the post-match presentation. "I've never seen so many balls fall in different areas.

"Sometimes, that's how the game goes. When you're not playing your best cricket, little 50-50 things go against you. We've got to try to make sure we turn those 50-50 towards us again.

"He was unbelievable again - and also Chris Morris, who hasn't played a lot of cricket for us, was excellent today."

Du Plessis was far less impressed by his side's batting, suggesting South Africa needed a player to perform like Rohit did for India after the Proteas stumbled to 227-9.

"Today was, once again, a great example of guys not batting through," he said.

"That's what you need in England - you need one guy batting through and then, if you get a total, your bowlers can put some pressure on. To have so many 30s and 40s was not acceptable."

However, Du Plessis gave some credit to India's attack, led by Jasprit Bumrah and Yuzvendra Chahal.

"I thought India were magnificent on a tough pitch," he said. "They bowled really well.

"Their bowling attack is strong - they've got all bases covered. They've got good fast bowling and then they've got spinners through the middle that always get wickets."