Highlights on BBC Two at 23:40 BST (BBC2 NI, 00:40)
Sri Lanka collapse from 116-2 to 203 all out
Four wickets for leg-spinner Tahir (4-27)
De Villiers takes brilliant catch & executes run-out
Tharanga 57, Perera 44*, Dickwella 41
Amla makes 112-ball century for SA
Du Plessis 75, Duminy 38*, Pradeep 2-54
Right, that's our cue to leave.
You can watch the highlights from today's game on BBC Two tonight at 23:40 BST (00:40 in NI).
We'll be back for India v Pakistan tomorrow, which is set to be a cracker at Edgbaston. Until then...
Ebony Rainford-Brent
Ex-England batter on BBC Test Match Special
South Africa have shown today why they're number one. They were under the pump and it started with their captain taking a brilliant catch, executing a superb run out and then Imran Tahir has been magnificent with the ball.
South Africa captain AB de Villiers: "It wasn't as true a wicket as the England v Bangladesh game so I was happy with our total. I thought Sri Lanka could chase it down, but also thought we should have enough. Credit to our openers for toughing it out for the first 10 overs and laying the platform. Hashim is a great asset to have. He's a great team man who contributes so much in the changing room, as well as scoring all those runs."
Sri Lanka captain Upul Tharanga: "We bowled well. We kept them down below 300, which is a good effort. We have to come back strongly against India, especially with our batting."
Man of the match Imran Tahir on TMS: "It's a big win for us. We've worked really hard over the past two weeks and to win is really pleasing.
"Credit goes to the batters. They set a target for us to bowl at.
"I always believe that my job is whatever is best of the team - that might be taking wickets or going at under three or four an over.
"I've been working really hard at my feeling. I'm pleased to get a run out. I can stand in the team meeting and celebrate that."
Sri Lanka were unable to get any oomph to the end of their innings as they slipped to a 96-run defeat in their Group B opener.
From there on, it was a little flat for Sri Lanka. There was the odd impressive start but South Africa, led by Imran Tahir, dried up the runs and Sri Lanka struggled. Tahir, who finished with figures of 4-27, also chipped in with a fine bit of fielding to rival his captain.
It took some brilliance from ABDV in the field, twice over, to stem the flow of runs. First, an absolute belter of a catch, which he somehow managed to make look easy...
And then this sterling pick-up-and-throw to run out Chandimal.
Right, let's have a little recap, shall we?
South Africa set Sri Lanka 300 to win their Group B opener, and they got off to a flier. Openers Dickwella and Tharanga took the attack to the South African openers and there was some sloppiness from fast bowler Kagiso Rabada. The openers put on 69 before Morne Morkel ended Dickwella's swashbuckling innings.
South Africa's Imran Tahir, who took 4-27: "Every time I put this jersey on, I feel honoured. I'm working hard and I hope this form continues in the tournament. We stuck to our plans today and won and that's very pleasing and encouraging."
Sri Lanka will need to improve their batting if they want to get past the group stages. Losing captain Angelo Mathews won't have helped, but once South Africa struck to end that early partnership, they struggled for momentum.
Charles Dagnall
BBC Test Match Special
Sri Lanka's seamers were very precise with their lines and their lengths. South Africa got off to a boring start.
Imran Tahir will finish with figures of 8.3-0-27-4. A cracking day's work.
Ebony Rainford-Brent
Ex-England batter on BBC Test Match Special
Sri Lanka could have taken this deeper, but South Africa were very good. In tournament cricket, it's about building momentum. It doesn't matter about winning pretty. They shut Sri Lanka down today and move on to the next match.
Pradeep c Duminy b Tahir 5 (SL 203 all out)
A win for South Africa! Fitting that it's Imran Tahir, who turned things back in South Africa's favour, who takes the final wicket as Pradeep goes for the big heave ho and ends up smacking the ball to long-on. That's an impressive win for South Africa.
Here are the three wickets that fell in quick succession, including that belter of a throw from Imran Tahir. Clearly he wasn't content with taking three wickets for next to nothing.
Charles Dagnall
BBC Test Match Special
Rabada kisses the surface. His wrist position is so good and it helps him generate the pace he does.
Perera 44, Pradeep 5
A boundary for Nuwan Pradeep! It's his second in ODI cricket! Two big swings and misses at Kagiso Rabada, before he finally gets an outside edge through extra cover and down to the boundary. Pradeep gets a single and then watches from the other end as Rabada whizzes a bouncer past Perera's nose. Perera then lashes a full delivery for another boundary!
Ebony Rainford-Brent
Ex-England batter on BBC Test Match Special
If I was Kusal Perera, I'd be looking for a nice 50 not out. Boost the average.
Perera, on 40, is happily driving everything up to mid-on and not taking a single. The field comes in to the final ball to try and keep Perera on strike, and Morris spears it wide. So Kagiso Rabada will get a bowl at the number 11.
#bbccricket
Dave Wood: Struggling to understand what Sri Lanka's gameplan was here. 87-1 off the first 10 should have been game over.