Usain Bolt bids for his first gold of the 2016 Olympics as the men's 100m takes centre stage as the final event of a busy Sunday in Rio.
The Jamaican coasted through his first round on Saturday, and he will return for the semi-final and then at 2.25am he will expect to contest the final and defend the title he won so thrillingly in London in 2012 and Beijing in 2008.
For the 'fastest man in the world' it is the first leg of what would be an unprecedented triple-triple, having claimed the 100m, 200m and 4x100m relay at each of the last two Olympic Games - Justin Gatlin is likely to be his chief rival for gold.
Golf and tennis have their critics as to whether they should be included at the Games, but both have produced memorable tournaments and will crown their Olympic champions.
In the golf, Justin Rose leads Henrik Stenson by one shot and a thrilling finish is in store, while Andy Murray meets Juan Martin Del Potro in the gold medal match.
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Murray and Rose will go for gold while in cycling's individual pursuit final GB's Jason Kenny and Callum Skinner will face off for gold with the loser guaranteed silver.
Chijindu Udah and James Dasaolu are in the men's 100m semi-finals, and face a battle to reach the final while Sonia Samuels and Alyson Dixon go in the women's marathon.
GB are well represented in the gymnastics final with Louis Smith and Max Whitlock in the men's pommel horse final and Whitlock joined by Kristian Thomas in the men's floor final.
At the aquatics centre, Grace Reid and Rebecca Gallantree go in the women's 3m springboard final while Katie Clark and Olivia Federici in the synchronised swimming duet event.
Nick Dempsey has all but secured silver in the men's windsurfing and that is likely to be confirmed on a busy day on the sea.
Going for Gold
Four medals will be won in the athletics stadium (men's 100m and 400m, women's triple jump and marathon) while boxing will crown their second champion of 2016 in the men's light flyweight division.
Three more medals will be decided in the tennis as Murray and Del Potro do battle for the men's singles title, the women's doubles and mixed doubles title will also be decided.
And golf will see it's first gold medal winner since 1908 when the men's singles title is decided.
One medal will be won in the veldodrome in the men's sprint while the individual apparatus finals get underway in both the men's and women's gymnastics.
For the men, it's the floor and pommel horse for the women it's the vault and the uneven bars where the unbelievable Simone Biles will look to add to the two golds she has already won, she goes in the vault.
Medals will also be won in diving, fencing, sailing, shooting, weightlifting and wrestling.
What Not to Miss
The 100m is always a blink and you will miss it event but the chance to watch Bolt should never be missed but also on the track the men's 400m has stardust sprinkled across it as LaShawn Merritt and Wayde Van Niekerk look to challenge the brilliant Kirani James for the gold medal.