Morne Morkel's radar is a bit off early in the 11th over as not even a full-length dive from Quinton de Kock can stop a loose one, and it is two wides. Thirimanne drives one for a single in the only other scoring shot of the over.

Michael Vaughan
Ex-England captain on BBC Test Match Special

"Thirimanne's in good form, so a very clever thought to send him in at number four rather than risk Jayawardene just yet. Sri Lanka know how to play one-day cricket - they rip up the manual and do what feels right on a particular day."

Sri Lanka 35-2 (10 overs)

Batsmen: Sangakkara 2*, Thirimanne 27*

Fall of wickets: 3-1 (K Perera 3), 4-2 (Dilshan 0)

Bowling figures: Steyn 5-2-13-1, Abbott 3-1-11-1, Morkel 2-0-11-0

Sri Lanka won toss

Scorecard

Brave and powerful from Thirimanne. He goes over the top from Dale Steyn and that's three boundaries in two overs. Thirimanne has had a mixed tournament so far. His best score was an unbeaten 139 against England and he also made half-centuries against New Zealand (65) and Bangladesh (52). On the flip side he only made scores of zero, one and four against Afghanistan, Australia and Scotland respectively.

Image source, AP

Jay: South Africa should be worried. The Sri Lankan run rate has sky rocketed from one an over a choke-inducing three runs per over .

There are hands on heads among the South Africans as the ball is in the air. Rilee Rossouw flings himself to his left at point and narrowly misses Lahiru Thirimanne's drive. The ball ends up going for four, before another Thirimanne drive off the next ball also ends up finding the boundary. South Africa have been on top, but will want to stop this partnership from growing any further.

Image source, Getty Images

Michael Vaughan
Ex-England captain on BBC Test Match Special

"You can see Sangakkara's trying to bat his way out of this pressure zone. That's why I'd go with a more attacking field, such as another slip or a fifth slip. New Zealand under McCullum would have four slips right now."

Listen to Test Match Special commentary via the audio icon.

It is a perfect day in Sydney. Lovely blue sky. And it will be South Africa who have enjoyed the sunshine so far. Their three bowlers have been hostile, picked up two Sri Lankan wickets and kept the score down.

Sangakkara is the most in-form player in the competition with four centuries in a row. He has one run off 22 balls, a Chris Tavare-style innings so far. Another maiden from South Africa.

Jonathan Agnew
BBC Test Match Special

"Morkel wasn't happy there. If that was the last ball of a World Cup final and called as a no-ball, it would have been quite tight."

It is our first look at Morne Morkel, who has been excellent this tournament, taking 13 wickets in his six matches so far. His first four balls are decent, Sangakkara gets a single to finally get off the mark after 15 scoreless deliveries before Morkel's front-foot no-ball gives Sri Lanka a free hit, but Thirimanne wastes the gift.

Ajit Abhyankar: I think the early wicket of Perera will not have much impact on SL batting. We should see a score of 280+ on the board.

vanhunks: Two wickets down. Now it's game on!

Vic Marks
Ex-England spinner on BBC Test Match Special

"I think both sides would have batted first. There's this odd statistic that South Africa have never won a sudden-death match in the World Cup. I always think that 1999 semi-final against Australia in England was the best game of one-day cricket I've ever seen - 213 v 213, and it just ebbed and flowed. Fantastic tension at the end, and chaos, and South Africa couldn't quite make it."

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South Africa may need to be changing their pillows at their hotel then. Dale Steyn gets treatment from the physio, who prods around at the top of Steyn's back as the bowler winces in pain.

Lahiru Thirimanne gets the first boundary of the match and it has taken until the sixth over. Then just like London buses, you wait ages for one, and two come along. Two identical, but lovely, shots between point and cover. Two boundaries.

Image source, Reuters

Michael Vaughan
Ex-England captain on BBC Test Match Special

"Steyn's injury looks like when you sleep on a dodgy pillow, and you get a crick in the bottom of your neck. What has been noticeable is the way South Africa have bowled a very full length, and got Sri Lanka on the front foot."

Worrying signs for South Africa as Dale Steyn looks to have picked up an injury, as he is holding the top of his back, in between the shoulder blades. One to keep an eye on.

Vic Marks
Ex-England spinner on BBC Test Match Special

"It's an awful start for Sri Lanka - the toss seemed to be an important, not so much now with the score 4-2. It looked like it wasn't going to carry, but a good catch from Du Plessis. Looks like a change in the batting order with Thirimanne coming in - South Africa are doing everything right so far and not giving anything away."

Listen to Test Match Special commentary via the audio icon.

Stephan Shemilt
BBC Sport in Sydney

"As Quinton de Kock took his brilliant diving effort, Mark Nicholas, sitting behind me, proclaimed "that is brilliant". Just as Dilshan edged towards Du Plessis, Simon Mann called "out". These commentators know a thing or two."

Image source, Reuters

Disaster for Sri Lanka. And that's two gone. Tillakaratne Dilshan goes without scoring. He got a thick outside edge, attempting to cut one away. It is another lively delivery from Dale Steyn and Faf du Plessis, at second slip, swoops to his right to take an excellent low catch.

Scorecard

Image source, AP

We have only had seven deliveries from one of the two balls in use, before it has to be changed. A lump has already been taken out of it. Kyle Abbott immediately bowls a wide. Let's blame the ball, shall we.

A huge shout as Kumar Sangakkara's heart skips a beat. He is yet to score, it is his only fifth ball and he is hit in front of the stumps. But umpire Nigel Long is not interested as the ball was heading over. Only one off the over.

Michael Blighe: I quite hope South Africa make it through. I think they've waited long enough, and they've been mighty entertaining so far!

Kishin Mahtani: Years of pain of supporting S Africa, please let it end today.