Kerber's in even more trouble here. She sends down a weak second serve at 73mph and proceeds to back hand into the net. Break point Rogers.

But the German composes herself and finds a couple of backhand winners to snatch back the points and hold.

'Go on Shelby,' scream a few partisan fans from the court two stands.

The American comes into the net and taps over for 30-0. She's not making any sudden movements here. Cool, calm and collected.

Kerber tries to challenge a big Rogers serve but it landed on the line.

And the German carelessly hits the net as the world number 70 holds to love.

She lost the first set but ninth seed Agnieszka Radwanska is a break up in the second set. We could be going the distance on Centre Court.

Novak Djokovic and Roger Federer may be waiting some time to make their appearance. The sportspeople in today's Royal Box are in for a treat of a day.

This match has been punctuated by some fine baseline rallies.

Rogers finds her 10th forehand winner as she stops Kerber's flow for 30-15.

But the German won't be denied. She holds and takes the game.

She really needs a break here, though.

Image source, Reuters

Jonathan Jurejko
BBC Sport at Wimbledon

There's a rumbling of excitement around Court Two. A shock is well and truly on the cards.

But the knowledgable SW19 punters also know Angie Kerber is a fighter. The German top seed might be a set and a break down but this is far from over, I'd suggest.

Either way this is going to be entertaining.

Liz Smylie
Former Wimbledon doubles champion on BBC TV

It's amazing what confidence can do. Shelby Rogers had never won in two previous attempts at Wimbledon but is now playing as if she is completely at home on this grass court.

Kerber will lose the number one ranking if she loses today.

The winners are coming thick and fast from Rogers now, while Kerber finds the net. Bam! There's the ace, and that's a love game to the American.

Watch again as Sam Querrey finishes his delayed match against Jo-Wilfried Tsonga in just five minutes.

Liz Smylie
Former Wimbledon doubles and mixed doubles champion

Shelby Rogers has to continue doing what she has done so far in this match; good serving, good use of the court, going up to the ball. She will have to keep an eye on her unforced errors.

This is just a little scrappy from Kerber.

There's not much oomph behind the serve and she hands Rogers two break points, the ball landing right where she wants it.

The first is saved as Rogers floats a backhand into the net, but Kerber wallops a forehand wide. Rogers has the early break!

And here is some of the play that's helped Shelby Rogers take a first-set lead over world number one Angelique Kerber.

A slight wobble from Shelby Rogers, gifting Kerber three points as her grip slips and a few shots ping wide.

The American gets the advantage with a belting serve, following it up with a furious return, and tidies up the game with a fine ace.

Kerber tonks a forehand long but she's soon raising her racquet in apology as a little wobble off the net falls in her favour. 30-30.

Up to the net now, Kerber trying to smash a winner, but her first attempt isn't powerful enough and Rogers manages to return in.She follows it up with a better attempt, mind, and that'll be a hold first up.

Barry Davies
BBC Sport commentator

The crowd have sensed that this could be a surprise right from the word go, they can feel it.

What's Angie Kerber got in her locker?

She'll serve to get the second set going.

Kerber moves 15-30 to the good as Rogers nets again but we're level again as the German shoots long with a backhand.

Kerber then challenges a call on the far side but her backhand is well out. Rogers brings up set point.

And the world number one hands it to her opponent as she sends her final ball wide.

Court two drama!

Image source, Getty Images

Jonathan Jurejko
BBC Sport at Wimbledon

Suddenly the press seats have got busier. Particularly with German media. They sniff a story brewing...

Nope, Kerber's not giving in either.

The German moves to 40-15 and holds with relative ease as Rogers finds the net with a backhand.

Rogers to serve for the set.

Liz Smylie
Former Wimbledon doubles and mixed doubles champion

Anyone that hits the ball like Rogers, has good serving capabilities and has the sort of variety she does, will give Kerber problems.

Kerber is very good at moving her opponent side to side, basing herself in the middle of the court and making her opponent play. She's a tough competitor, as you would expect from the number one player in the world.

Shelby Rogers is still on top on court two.

The American sees out her service game with an ace and she'll make the world number one serve to stay in the set.

Could we possibly have another upset on the cards today?

Image source, PA