India recover from 2-3 to win by six wickets
Kohli (85) & Rahul put on 165 for fourth wicket
Marsh drops Kohli on 12
Australia struggle on slow, turning pitch - slumping to 199 all out
Warner (41) & Smith (46) top-score but lack fluency
Jadeja (3-28), Kuldeep (2-42) & Bumrah (2-35) star with the ball
Carlos Brathwaite
Ex-West Indies all-rounder on BBC Test Match Special
Josh Hazlewood is a difficult proposition at the best of times. But on a track like this, where some balls go through a bit slow and others don't, he must be so hard to pick.
A mightily relieved Virat Kohli takes a single from an edge to deep third. He moves to 13.
Skied by Kohli off Hazlewood, should be out... dropped!
Slower short ball from the Australian seamer, Kohli is through the hook shot early and the ball flies in the air. Mitchell Marsh runs round from a short mid-wicket to try and take the chance, Alex Carey also closes on the ball - a sliding Marsh gets there first but the ball spills off his torso and onto the grass.
Should that have been Carey's?
Carlos Brathwaite
Ex-West Indies all-rounder on BBC Test Match Special
I prefer India's batting approach even though they have lost early wickets. They are showing attacking intent and trying to force changes from the Australia bowlers.
Pat Cummins brings himself onto bowl in place of Starc.
The Indian batters take a single each off the Australia captain, Rahul cutting to deep third and Kohli taking a run through mid-wicket.
Carlos Brathwaite
Ex-West Indies all-rounder on BBC Test Match Special
The shelf life of this seam attack probably has until the end of the powerplay. A lot rests on how far they get can into the India middle order before then and whether Adam Zampa can take further wickets.
Oooh, Hazlewood beats the bat of a driving Kohli! Short of length, flying through to Alex Carey behind the stumps.
The Indian legend responds in style, smacking the next delivery dismissively down the ground for four. He was on one leg on the swivel, and didn't even watch the ball go all the way to the ropes.
He fires the final ball of the over off his legs and Starc cuts it off at the boundary, running around at deep square. Just two runs there.
Just the two runs from Starc's third over, a wide and a Kohli nudge to mid-off.
The Australian seamer is visibly panting at the end of his over and his hair is drenched in sweat. It's a warm night in Chennai.
Geoff Lemon
BBC Test Match Special commentator
This is still India's game given how well they bowled. They can recover from this rocky start.
Though if Kohli gets out that calculus changes.
A first four of the innings for KL Rahul, who came in at five for India.
He times the drive perfectly off Hazlewood's final ball, sending the ball past a despairing David Warner.
#bbccricket
Tom Linden-McCarron: If stadiums are half-empty for an Indian World Cup match versus Australia in India, then unfortunately, as much as I love the format, ODIs' time may be up.
Virat Kohli ensures he won't be a fourth duck for India, taking two through square leg. That's the first runs off the bat in this innings.
He then flashes at a wide one from Hazlewood - there's definite nerves out there.
Aaron Finch
Former Australia captain on BBC Test Match Special
A little bit of width from Josh Hazlewood and Shreyas Iyer lobs it to David Warner. No footwork and the simplest of chances. If you weren't here you wouldn't believe it! Often on surfaces where the top gets disturbed the fast bowlers are just as effective as the spin bowlers.
Prakash Wakankar
BBC Test Match Special
Straight down the throat of David Warner. Australia are not just on top but dictating terms to India.
Iyer c Warner b Hazlewood (Ind 2-3)
And another! New batter Shreyas Iyer drives straight to David Warner at short cover, who takes the catch fingers up at shoulder height and then throws his hands in the air in delight.
A three-ball duck for Iyer, the third one of this young innings, and a double wicket maiden for Josh Hazlewood - what a start for Australia!
Prakash Wakankar
BBC Test Match Special
Australia with a dream start and India in big trouble already.
Aaron Finch
Former Australia captain on BBC Test Match Special
It was a wobble seam from Josh Hazlewood which hit the crack and nipped back.
Rohit lbw b Hazlewood 0 (Ind 2-2)
No, that's gone!
Rohit seemed confident of over-turning the decision but that looked pretty plumb - it struck high on the pad but he was back in his crease.
If India were anticipating a simple chase, they might have to think again.
Prakash Wakankar
BBC Test Match Special
Rohit Sharma reviewed it straight away but this could be a massive blow.
Josh Hazlewood strikes Rohit Sharma high on the pad! The umpire's finger goes up, Rohit Sharma appeals it straight away.