Postpublished at 04:21 Greenwich Mean Time 28 February 2015
Geoffrey Boycott
Ex-England batsman on BBC Test Match Special
"All they need from Williamson is just to bat. New Zealand have got hitters and he has plenty of overs. Just play."
India beat UAE by nine wickets in Pool B
Ind 104-1 (18.5 overs); Rohit 57 not out
UAE 102 all out (won toss); Ashwin 4-25
NZ beat Australia by one wicket in Pool A
NZ 152-9 (23.1 overs); Starc 6-28
Aus 151 (32.2 overs): Boult 5-27
Phil Dawkes and Michael Emons
Geoffrey Boycott
Ex-England batsman on BBC Test Match Special
"All they need from Williamson is just to bat. New Zealand have got hitters and he has plenty of overs. Just play."
He has just been dropped, but Brendon McCullum is soon getting the home fans cheering again. He gets an outside edge on an attempted pull shot with the ball flying between wicketkeeper and slip for four.
Geoffrey Boycott
Ex-England batsman on BBC Test Match Special
"It was brute force. He smashed it. Starc got his right hand on it but he'd have been lucky to get hold of that."
If Australia are to have any opportunity, they have to hold on to every chance. Mitchell Starc's delivery is batted with force back at him by Brendon McCullum and the bowler cannot take what would've been a one-handed catch.
Geoffrey Boycott
Ex-England batsman on BBC Test Match Special
"AB de Villiers can do anything - off side, on side, over the top, over the wicketkeeper. McCullum comes at you - you don't often see him go back."
Brendon McCullum, now wearing an arm guard after being hit on the arm by Mitchell Johnson, flicks one off the pads for a single to bring Kane Williamson on to the strike. He gets off the mark soon afterwards with a boundary as he nips it down leg side to beat the fine leg fielder.
If McCullum is in pain, he's doing his best not to show it. He gets the strike again and bashes one back past bowler Johnson for another four. New Zealand going at 10 an over. This match may not last long.
Scott Lennon:, external McCullum and De Villiers are playing a different game! Stick cricket perhaps!
Kane Williamson is the new man in. He has made scores of 57, 38 and nine not out against Sri Lanka, Scotland and England respectively so far in this tournament.
Jeremy Coney
Ex-New Zealand captain on BBC Test Match Special
"It was just a little chipped effort - it didn't give me the impression he was trying to hit the ball hard. Mid-off moved slight to his right. Easy. Off you go."
Listen to ball-by-ball TMS commentary by clicking on the audio icon.
It is a start for Australia. But they need a lot more. And quickly. Martin Guptill is the first New Zealand man out. He doesn't get much power on it, but Cummins produces a nice dive at mid-off to take the chance.
Some macho bravado going on there. McCullum looks desperate to show he is not in pain. He gets some treatment on it, but refuses to go off the field. Next ball he faces, he cuts for four. Great play from a tough guy.
But will that arm injury affect him later in the innings? New Zealand 39-0 after 14 came off the third over.
Joe Wedgwood:, external Nothing better than watching your Aussie flatmate getting gradually saddened wicket by wicket!
Former West Indies fast bowler Tino Best: "That's what I'm talking about - sweet blow. Hit that out the park now Mad Max."
Incredible hitting from New Zealand and Australia look like they have no idea what to do. They are changing the field before almost every ball. A six for McCullum over point, followed by a four over cover.
Well, that's the way to stop him. Mitchell Johnson sends one in short and hits McCullum near the elbow, missing the arm guard. It has already swelled up and left him with a horrible bruise.
Jordan Davies:, external Brendan McCullum, a one man machine with the sole aim of tearing apart bowling line-ups.
Sam Johnson:, external What's the record for fastest World Cup run chase? I bet McCullum knows the answer.
Jeremy Coney
Ex-New Zealand captain on BBC Test Match Special
"McCullum does upset bowling attacks - he doesn't allow a bowler to enslave him. He's instinctive and he's free. He plays on his own terms."
Listen to ball-by-ball TMS commentary by clicking on the audio icon.
Brendon McCullum wants to finish this one quickly. He charges down the wicket as he looks to launch Mitchell Starc first ball. The bowler sees him coming and sends it wide.
But he doesn't have as much luck with the second ball, which McCullum, showing some nifty footwork, dances down to meet and launches over extra cover for six. That's the 162nd six of the tournament, for those keeping count.
Two balls later. Straight, hard, back where it came from. Four. Wonderful entertainment from McCullum and New Zealand.
Antony Stewart:, external Just got in. New Zealand, what are you doing!? They are real contenders. Either they're going to win #CWC15, or De Villiers will.
To be fair, it is a good response from Mitchell Johnson. No more runs come from the over.
The television cameras focus on some of the home fans. 'A walk in the park' reads one message. I'm not sure if it was a pre-prepared sign, or if somehow has frantically been reaching for a felt tip in between innings. But we get the point.
Keep it tight. Keep it tight. Well, maybe not. As starts goes, it is an absolute disaster.
Mitchell Johnson's first delivery is glanced for four. And it is a front-foot no-ball as well. Martin Guptill then slaps the free hit for six. New Zealand 11-0. Off one ball.
Anyone else enjoying this greatly? Australia not so cocky at the moment.