Support for Richard Kruse from GB team-mate Laurence Halsted.

Image source, Getty Images

Yep, Andy Murray, flag-bearer at the Opening Ceremony, two-time Wimbledon champion and all round toast of the Great Britain begins his Olympic campaign(s) today. 

First up he's taking on Viktor Troicki of Serbia, before he takes to court again laterwithbrother Jamiein the men's doubles - they're up against home favourites Thomaz Bellucci and Andre Sa.

Image source, Getty Images

So, who can challenge Lizzie Armitstead for gold?

Well, it's a matter of double Dutch.

There's three-time world champion Marianne Vos, who is seen as the don of the sport in recent years. She had injury problems in 2015, so was unable to compete against Armitstead at the world championships.

The favourite, though, remains Anna van der Breggen, who was runner-up to Armistead at last year's worlds and also took silver in the time trial. She claimed titles at La Course and in the Giro Rosa in 2015.

The question will be whether the Netherlands team have selected a leader, or will let the pair race each other.

All of them are in the peloton, with a breakaway up the road.

Game, set and match.

A good work out really for the defending champion. Gavrilova played some really good tennis and pushed Williams at times, but Serena showed her class at the big moments.

Up next, it's Andy Murray time.

Alistair Magowan
BBC Sport in Rio

Image source, BBC Sport

Managed to grab a word with TV adventurer Steve Backshall, the fiance of defending women's pairs Olympic champion Helen Glover, about the effect that re-scheduling could have on the friends and family of the Great Britain athletes. 

Both Glover and rowing partner Heather Stanning had their opening heats cancelled this morning because of high winds. 

Backshall, who arrived in Rio last night, said: "The big worry now is that having cancelled a whole day of the regatta, it's going to have an enormous effect on the schedules and it's going to start piling up.

"If finals get put back then a lot of the friends and family I've been sat with won't be able to see their partners, their brothers, their sisters or their mums competing and that's going to be heartbreaking."

Richard Kruse will face either world silver medallist Alexander Massialas of America or Girgio Avola, a member of the world champion Italy team, in his semi-final at 22:30 BST.

If he wins, he's in the gold medal bout. If he loses, he's in a bronze play-off.

Wonderful stuff from GB's Richard Kruse. He's into the foil semi-final with a 15-13 win over American Gerek Meinhardt.

He's one win away from at least a silver medal.

We have an answer to Tom's question at 18:03 - Yulia Efimova is greeted by booing.

It hasn't stopped her winning heat five, though. She's clocked 1 minute and 5.79 seconds to go fastest overall.

In the same heat, Britain's Chloe Tutton finishes in 1 minute and 6.88 seconds.

Britain's David Florence powers down the course to post the fastest time (94.11) by over two seconds with just three more paddlers to come. Florence will be back for the final in two days' time, no doubt about that.

Tom Fordyce
Chief sports writer in Rio

Just a few moments here until the 100m breaststroke heat of controversial Russian Yulia Efimova, banned for 16 months in 2013 after traces of an anabolic steroid were found in her system and only cleared to compete here a day ago by the Court for Arbitration in Sport. 

What sort of reaction will the reigning world champion get from this sparse Rio crowd?

Here's a turn up for the books. Britain's Emma Pooley has launched a surprise attack from the front of the peloton. She's followed by Australian Gacie Elvin.

Is it an attack for her own medal hopes, or to try and exhaust members of the peloton for Lizzie Armitstead?

Great Britain's Molly Renshaw has finished second in heat three of the women's 100m breaststroke.

She finished in a time of 1 minute 7.92 seconds; now we wait to see if that is quick enough for her to progress.

Fellow Briton Chloe Tutton goes in heat five.

Watch live swimming here.

Richard Kruse is edging closer to a foil semi-final. He's 10-7 up - five more points needed to seal it.

Yup. They're into the last eight, Louis, after winning all of their pool matches. Their quarter-final with Fiji is at 22:00 BST.

Great start from GB's Richard Kruse, who takes a 5-2 lead in his foil semi-final.

It's first to 15 or whoever has the highest score after three three-minute periods.

Make that a 5-3 lead as his American opponent Gerek Meinhardt hits back.

In case you missed it, here's another chance to watch Britain's Joshua Buatsi achieve the first stoppage of the Olympic boxing tournament with a brutal display against Uganda's Kennedy Katende in the light-heavyweight division.

Aimee Lewis
BBC Sport in Rio

The wind isn't stopping play on Centre Court, and neither is it able to halt what is likely to be a straight-sets win for Serena Williams over Australia's Daria Gavrilova.

The pair took part in a wonderful rally towards the end of the first set, one which ended in Gavrilova's favour and had the crowd on their feet applauding. 

It's just a shame this match isn't being played out before a full stadium, but it'd unlikely be full even if it were a first-round Grand Slam event. 

The phrase "carbon-munching" is not used nearly enough.

Tom Fordyce
Chief sports writer in Rio

Breezy outside means breezy inside at the Olympics Aquatic Centre - there are 15,000 tiny holes designed into the exterior of the building, which act as a natural ventilation system in place of carbon-munching aircon machines. A breeze too for James Guy in the 200m freestyle, into tonight's semi-finals in easy shape.

Britain's Richard Kruse has started his men's foil quarter-final against American Gerek Meinhardt.

Head over here to watch it.