Richard Owen: Great fright by Joshua Buatsi

Hal in London: Superb display from Croydon's finest Joshua Buatsi in the light heavyweight. KO vs 3rd seed.

While Joshua Buatsi has pulled off a surprise, Andy Murray is doing something wholly unsurprising. At 5-1 up, he is serving for the first set against Fabio Fognini. A place in the quarters up for grabs, remember.

Yep, in what has been a pretty disappointing campaign for GB's boxers thus far, Joshua Buatsi has sprung something of a surprise.

Buatsi has reached the quarter-finals of the men's light-heavyweight with a third-round stoppage of Uzbekistan's Elshod Rasulov, the tournament's number three seed.

So, are you up to speed with this? There are two GB boats going in canoeing finals in the next hour or so. David Florence and Richard Hounslow are in the C2 final from 18:15, with Fiona Pennie lining up in the K1 final from 19:00. Two medal chances.

There's other good news for GB in Rio too...

Helen Reeves
Olympic bronze medallist and BBC canoeing pundit

"A brilliant display of slalom paddling by Fiona Pennie. She nailed the downstream, nine and ten, that is where she got that time at the top split. She will be looking to get even across that time a fraction quicker."

Nailed by Fiona Pennie, who secures her place in the final. The Scot is the second fastest qualifier with two boats still to go. The final is at 19:00.

First upstream gate, spin, penalties avoided. Looking good...

Not the greatest start, but at the first split she's more than a second and a half inside the fastest time so far...

Pennie is in the gate, sticking out her tongue as she begins. Under way...

Fiona Pennie is the next to go. At the moment, a time inside 108.58 seconds will be good enough for a place in the final.

No such early drama for Andy Murray, though. He's already a break up on Fabio Fognini.

Anyway, to canoeing...

Image source, BBC Sport

In the badminton women's doubles competition GB's Lauren Smith and Heather Olver have lost the first end 21-17 against their Malaysian opponents.

There's still hope in the best of three end match but a comeback is needed against the Commonwealth Games gold medalists.

Sticking with water, the men's 50m freestyle heats have been taking place this afternoon. Great Britain's Ben Proud has made it to the semi-finals and you can see how he did it right here...

Luke Reddy
BBC Sport in Rio

Guess who I've just been lucky enough to meet at the canoe slalom?

Image source, .

Image source, .

Pennie, a 33-year-old Scot, missed out on qualifying for the London Olympics but has since won the 2013 European title and silver at the 2014 world championships.

It was around this time yesterday that we started to take notice of Joe Clarke... 

We'll be keeping an eye on Murray, but our focus will soon return to canoeing, where Fiona Pennie will be looking for a place in the women's K1 final.

Pennie is out of the gate at 17:51.

Richard Oliver: Please can someone get a message to the fan watching Andy Murray to get his Union Jack the right way up! Thanks.