04:16: That is where we wrap up our coverage for today, though. We’ll be back tomorrow with more as manic track action continues. 

**

04:15: After Bolt’s race, while he was being mobbed by reporters, he told everyone to hold up, jotted to the stands and congratulated the South African champ. Lovely moment.

**

04:14: Wayde’s race was so good, even Botl left stunned.

Usain Bolt’s reaction to Wayde van Niekerk’s WR 43.03 in the 400m final. #Rio2016 pic.twitter.com/GJIaMLGzIZ

— Stephen Nelson (@Stephen__Nelson) August 15, 2016

**

04:12: Usain Bolt cruised into Olympic history, winning his thrid gold in the 100m while South Africa’s Akani Simbine finished fifth, but made history of his own, becoming the first male South African to make the final of the event since the country’s readmission to sport. 

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04:10: What a night we’ve had. If you woke up to watch, you might never sleep again. As somebody Tweeted earlier: I feel like I could bench press a rhino. If you slept in, shame. The night belonged to South Africa’s Wayde van Niekerk, who smashed the 400m world record to win gold in an absolutely incredible race. Despite “running blind” Van Niekerk blitzed it and left his opponents in his dust. It was exceptional. Since the heats, Van Niekerk has looked so, so good. 

The new 400m Olympic champion @WaydeDreamer has a message for @MJGold after breaking his world record… https://t.co/gdgl775ptL

— BBC Sport (@BBCSport) August 15, 2016

**

03:27: Sorry for the radio silence, I had all this adrenaline and had to go run around the block. Bolt has comfortably won the 100m. Simbine had a good race, but just couldn’t get over the line fast enough. He’s been really impressive at these Olympics, though. And he has a long future ahead.

**

03:03: This is just…this is wow….Van Niekerk has absolutely obliterated the world record. He almost went inside 43 seconds. He ran it in 43.03. Van Niekerk was absolutely exceptional. Balls of Steel. 

**

03:01: Wayde van Niekerk is blind on the outside and he is off like a rocket. There’s daylight between him, Merrit and James….but wow. Wow. Wow. Wayde has done it!

**

02:23: Pretty historical stuff from Simbine.

.@AkaniSimbine becomes the first SA male sprinter since Danie Joubert in LA 1932 to make it into the 100m final at the Olympics. #IOLYMPICS

— Ockert de Villiers (@ockertde) August 15, 2016

**

02:18 Simbine has cracked it! That’s going to be one heck of a race. These guys are looking fierce. Not sure we’ve seen the best from Simbine yet, but it’s going to take something incredible to beat Bolt. That final is coming up at 03:25. There’s the small matter of a 400m final to come first…in about 40 minutes.

***

02:15: Final semi coming up. It’s got Yohan Blake and Justin Gatlin in the mix..Gatlin wins, but not quite as impressie as Bolt. Blake is second. Only Gatlin under 10 seconds…9.94 in fact.

**

02:10: Of course Bolt wins it. From about 60m, Bolt put on the after burners and wins in 9.86. Simbine gets a little hug from him as he walks off the track. Bolt started slowly, but as soon as he got going, he was cruising. He cruised so quickly he even had time to look left and right. My Sub B athletics coach told me never to look left or right. Shows what she knew. Andre de Grasse was second, also under the ten second mark. No one else was. So Simbine still in with a shot.

**

02:08: There’s been a false start from Fisher, the man from Bahrain. He’s been given a red card. What a bummer.

**

02:07: Usain Bolt is the AB de Villiers of running. Crowd goes wild as he is announced. 

**

02:05: Jimmy Vicaut is first, Benn Youssef second. Simbine’s time was  9.98. We’re onto semifinal two to see if he cracks it…Andy Murray has beaten Del Potro to win gold in the tennis, by the way. He wins 7-5, 4-6, 6-2, 7-5.  But enough of that, Bolt is about to run.

**

02:01: Simbine up now. He looks pretty chilled for a guy who is about to run such an important race. Simbine starts off steadily, straightens up and now we’re waiting for confirmation on whether he’s second or third…oh he’s second. By one hundredth of a second.

**

01:37: Phyllis Francis has won the first semi-final of the women’s 400m in 50.31. Jamaica’s Stephenie Ann McPherson ends in second. In the second semi, Jamaica’s Shericka Jackson has run 49.83…and she can’t believe it. She looks at the board stunned. Natasha Hastings is also through after finishing second.

**

01:09: That partisan crowd have started to take their shirts off and circle them around their heads. Like at the soccer. Things are feisty.  But we’re switching over to the track action now…but we’ll check back on the tennis intermittently. 

**

00:17: Unbelievable! Del Potro manages to take the second set against the 2012 Olympic champion despite appearing to be carrying a large wardrobe around the court on his back. We’ll keep an eye on this titanic tussle as the track ‘n field gets going. If Juan Martin can get out of his chair again.

**

00:09: Told you it could be a late one. Del Potro and Murray are slugging it out and, frankly, both look knackered. The Argentinian is serving to make it one set apiece under the lights with a partisan – and increasingly sozzled – South American crowd right behind him. Ole! 

**

22:34: The men’s singles tennis final is also on the go as you read this. Great Britain’s Grand Slam champ Andy Murray is a break up in the first set against Juan Martin del Potro, who has only had to pop down the road from Argentina to Rio for the event. It’s best of five sets in the final, so it could be a late one.

**

21:59: All the track and field fun to come later on. In the meantime, it’s all about things like the men’s omnium (don’t ask) and greco roman wrestling (definitely don’t ask).

**

21:10: Rose was born in Johannesburg. Claim his gold medal if you want.

**

21:09: News in from the golf, Justin Rose has won. This from the BBC:

“Rose, 36, was level with Stenson on 15 under par after 17 holes but the Swede bogeyed the last while Rose sank a birdie putt to win by two shots. The 2013 US Open champion closed with a four-under-par 67 to win on 16 under. Open champion Stenson (68) took silver with American Matt Kuchar carding a 63 to take bronze on 13 under.”

**

18:14: Tonight is the biggie, though. At 2am, Akani Simbine will race in the 100m semi-finals and at 3 am, Wayde van Niekerk goes for gold in the 400m finals. Simbine could have a chance to do the same at 3:25, if he progresses to the finals. We’re here to keep you updated.

**

18:13: In the women’s marathon, Lebo Phalula finished 63rd in a time of 2hr 41min 46sec, Christine Kalmer ended in 96th position with a time of 2:48:24. Irvette van Zyl was injured and did not start. 

**

18:11: In the golf, South Africa has been largely under par. Well, over par, actually, but you know what we mean. Jaco van Zyl did manage to hit a hole in one.

**

18:07: We’ll update you on what has already happened today shortly, but first…please enjoy this moment.

**

18:05: After a manic day on Saturday is a bit more chilled. Well, if you consider the final of the 400m and the 100m to be chilled. 

Photo: 2016 Rio Olympics – Athletics – Semifinal – Men’s 400m Semifinals – Olympic Stadium – Rio de Janeiro, Brazil – 13/08/2016. Wayde van Niekerk (RSA) of South Africa. REUTERS/Lucy Nicholson