A first change from Sri Lanka skipper Angelo Mathews, who decides that if you want a job done properly, you've got to do it yourself. He makes a good start too, opening up with three dots before McCullum pinches a single to the usually electric Dilshan at point. Is the veteran struggling after getting his ankle strapped in the warm-up? A much better over for Sri Lanka, just one from it.

A really good slower ball from Malinga bamboozles McCullum and hits the batsman on the pad, but it's just going down leg, much to the bowler's chagrin. Guptill keeps the scoreboard ticking over with a flicked three though cow corner and single to mid-on.

Now Martin Guptill gets in on the boundary-hitting act. He begins by clipping a wayward Kulasekara delivery to the fine leg fence, then pierces a populated off-side field with a slap through point. Sri Lanka need to stem this flow of runs, and fast.

Bharathan, California, USA: Much awaited moment is here. Very excited. Would be following the matches all the way through BBC text commentary. A favourite of mine.

Stephan Shemilt
BBC Sport in Melbourne

"Saturday morning in Melbourne, as seen from a 16th-floor window. There was a storm last night and more rain early today, but the forecast is for it to clear up before play begins at 14:30 local time and the early signs are that might be correct. Still, it will probably be England who were happier when they pulled back the curtains."

A better over from Malinga, who checks New Zealand's momentum by conceding just two runs from his first five deliveries. But then the bowler blots his copybook with a front-foot new ball. It's not too costly though, as Guptill can only manage a two off the free hit.

Andy Moore:, external I like the look of the New Zealand team. Think they have good solid cricketers and x-factor players in McCullum and Williamson.

Pete Naylor:, external Baz on strike, flays it over the covers for four. Says it all - New Zealand are here and ready to cause an upset!

Jeremy Coney
Ex-New Zealand captain on BBC Test Match Special

Image source, Reuters

"A decent start from New Zealand. McCullum's got the foot down - can he keep it going?"

Listen to TMS commentary on BBC Radio 5 live sports extra

Nuwan Kulasekara has dismissed Martin Guptill on six occasions in ODIs, and the batsman is showing him plenty of respect, dealing in singles so far. Not so McCullum, who picks up his third boundary with a delicious late nudge down to the third man boundary.

Jeremy Coney
Ex-New Zealand captain on BBC Test Match Special

"Malinga's only had a couple of warm-up games before today. The pace of the pitch looks comfortable for batting, there's not excessive pace or bounce."

Lasith Malinga takes the other new ball for Sri Lanka - his corkscrew curls bobbing in familiar fashion as he runs in to bowl. Martin Guptill eases one off his legs through midwicket, but an excellent chase from Suranga Lakmal just prevents the boundary. They run three. McCullum then maintains his 400 strike rate with a punchy square cut to the rope. What a start by the skipper.

Jeremy Coney
Ex-New Zealand captain on BBC Test Match Special

"Immediately Sangakkara comes up to the stumps for McCullum - the message is 'do not charge at our opening bowler'. But what a statement from McCullum - just the sort of start he needs."

Listen to TMS commentary on BBC Radio 5 live sports extra

We're treated to a rather incongruous 10-9-8 countdown before Nuwan Kulasekara gets us underway. The first ball of this World Cup is a gentle loosener outside off. In fact, he's having a bit of a struggle with his line - a wide follows, a rather anti-climactic way to record the first run of the tournament. Martin Guptill is in fairly watchful mode - as befits a man who has been dismissed first ball twice in recent ODIs - but he gets off the mark with a flicked single into the leg side. That brings Brendon McCullum on strike, and the captain doesn't disappoint - flaying his first ball over the covers for four.

Vic Marks
Ex-England spinner on BBC Test Match Special

"There's a big responsibility on Brendon McCullum in the town where he now lives. In a few minutes he'll take guard and set the tone for the whole World Cup."

Image source, Reuters

Martin Guptill and Brendon McCullum are trotting out to the wicket, the burly skipper windmilling his bat in ominous fashion. Sri Lanka have one last huddle. We're ready to go in Christchurch...

Andrew Samson
BBC Test Match Special statistician

"It will be Sri Lanka's sixth appearance on the opening day of World Cups and they have lost all of their five previous opening day matches.

"New Zealand will also be appearing for the sixth time on Opening Day. They have won four and lost one of their previous five. The only loss was to England at The Oval in 1983."

Ilyas Najib:, external We all need a drinks break after the marathon anthems of the two teams.

Ah. Unfortunately the weather gods have decided not to play ball on this momentous occasion. There's a bit of rain about, so it looks like there will be a small delay to the start of this match.

Vic Marks
Ex-England spinner on BBC Test Match Special

"There is a speck of rain in the air, but we don't think it's going to last for long. There is a huge feeling of anticipation in Christchurch - it's a very poignant place to start this World Cup after the city was wrecked in that earthquake four years ago."

Image source, Getty Images

It's time for the anthems in Christchurch. If you've watched much of Sri Lanka at World Cups before, you may recall that theirs is a rather long number - time to make a cup of tea.

Looks of steely determination on Kiwi faces as 'God Defend New Zealand' pipes up. This match is being played in Christchurch, a city that was devastated by an earthquake in 2011, so there's added emotion for this occasion.