India coach Rahul Dravid insisted Virat Kohli is "really focused" on winning the World Cup rather than any looming personal and professional landmarks as the hosts prepare to put their unbeaten record on the line against nearest pursuers South Africa.

Star batsman Kohli turns 35 on Sunday, when India -- who've already reached the semi-finals -- face the Proteas at Kolkata's Eden Gardens.

Kohli almost equalled Sachin Tendulkar's all-time record of 49 one-day international hundreds while making 88 against Sri Lanka in the presence of the 'Little Master' at Mumbai's Wankhede Stadium on Thursday.

But his innings helped pave the way for a crushing 302-run win, with Kohli now having scored 442 runs, including one hundred, from seven tournament innings at an average of over 88.

Dravid, himself once an outstanding India batsman, said Kohli's attitude and performances were indictive of his desire to win the World Cup for a second time, having previously lifted the trophy on home soil in 2011.

"I think Virat's been really relaxed and as you can see in his performances, batting really well for us," Dravid told a pre-match press conference on Saturday.

"I haven't noticed anything different. He's always been the same. He's always been professional, always been hard-working, always been switched on."

Dravid added: "I don't really think he's thinking too much about (ODI hundreds) 49 and 50, and probably certainly not about his birthday and getting a year older. I think he's been really focused on winning the tournament and playing some good cricket for us. I think he's doing that really well."

The rout of Sri Lanka also saw Shreyas Iyer come into form with a blistering 82 off just 56 balls, including six sixes, as he helped bolster India's total to 357-8.

"We wanted him to go hard," said Dravid. "To have that courage and the skill to be able to execute that performance, knowing he hadn't got runs in the last two-three games, I think speaks volumes about him as a person and his temperament."

'Under the radar' Jadeja 

India quicks Jasprit Bumrah, Mohammed Siraj and Mohammed Shami grabbed the headlines for their devastating displays as Sri Lanka were skittled out for just 55 -- the lowest completed total by any Test side at a World Cup.

But Dravid also acknowledged the impact of Ravindra Jadeja, with the left-arm spinner now the lone genuine all-rounder in India's squad after Hardik Pandya was ruled out of the rest of the World Cup on Saturday with an ankle injury.

"He has been exceptional in this tournament," said Dravid of Jadeja, averaging 41 down the order with the bat and just 23.33 with the ball.

"The kind of control he's given us through the middle, has been sensational...And then with the bat, it's not easy for someone like him because, batting at No 7, he doesn't play for three or four games, and then has to come in and play quite an important innings every time."

With Jadeja also a brilliant fielder, Dravid said: "He's a really great all-round package...and maybe gone under the radar a bit."

South Africa's place in the last four was secured by Pakistan's defeat of New Zealand on Saturday and Sunday's match could now be a dress rehearsal for the November 19 final in Ahmedabad.

But a cautious Dravid said: "What happens from here on in, is still two or three games to go.

"Both the teams, whether it's us or whether it's South Africa, we still need to earn the right to be there in Ahmedabad."