Del Potro's forehand is his weapon of choice.

But he can go with that and he can go with this - a wonderful lob on the turn that Kokkinakis can only smash into the net.

More net from the Aussie and it's 40-0 Delpo. Booming ace and it's level again.

Watch an exquisitely executed drop shot from Irina Falconi against Angelique Kerber.

Jonathan Jurejko
BBC Sport at Wimbledon

The Ward family might not be able to toast a double celebration tonight but son Alex, despite defeat by fellow Brit Kyle Edmund, certainly made his mum Sue happy on her 60th birthday.

"It has been a special day, although everyone keeps reminding me of my age! But it has been a wonderful way to spend it," she tells BBC Sport.

And while a victory for the world number 869 would have been the perfect present, Sue hopes both she and her son will be back in SW19 next year.

"I couldn't be prouder of him. I admire the way he is still plugging away at it," said Sue.

"The positive thing is this is going to be a springboard for more tennis and he'll be able to continue to improve."

John Inverdale
BBC Sport commentator

This is like a barbecue of game - you turn it one way and then the other, simmering at first then bringing it up to temperature.

Image source, Getty Images

This has been a stuttering show from Kerber.

She looked careless against Falconi's serve but she's breezed through her own service game, mixing up her pace to level.

Kokkinakis finds net but next point clatters a forehand winner back into the space Del Potro had just vacated.

The Aussie fires wide and it's 15-30 to Delpo. A terrific return to a stinging serve forces Kokkinakis to slice into the net. Two break points for JMDP.

A big serve saves one. A big serve saves the other.

A backhand passer slides wide though and Delpo has another break point. But another unreturned serve saves Kokkinakis.

Oh dear, Del Potro is on top in the point but makes a bad error on his backhand, missing the line and Kokkinakis has the advantage. He takes it this time, firing a deep backhand that Delpo can't return.

Watch a lovely backhand winner from Gael Monfils to break Daniel Brands' serve in the first set.

Falconi meets a spinning delivery in a bit of an awkward fashion, a drop shot on the move, and it bounces right on the line.

It's a loose game from Kerber, and Falconi will hold.

Kerber nails a drop shot but she's beaten by a supreme slap of a forehand from Falconi. Break back point!

And Falconi takes it! With a supreme slice of luck! A loose forehand clips the net and lands just on Kerber's side! She raises her racquet in apology.

Chance for Kokkinakis as he drags Del Potro out of shape to make it 15-30.

He sneaks in a backhand that foxes the Aussie to level, though.

Brilliant second serve makes it 40-30. Another big serve and that's game.

Image source, Reuters

After a 'bit of a battle' Miles Raonic comes out on top of the first set against Jan-Lennard Struff.

A 17-shot rally, both players darting behind the baseline, and it's Falconi who unfurls the winner with a fine forehand

Kerber brings up break point though, volleying and sending Falconi the wrong way, but a gentle lob upwards forces it to deuce.

The German gets the second break point though. She clenches her fist and turns to her coach, who nods in approval.

Image source, Reuters

OK, this is more like it, Del Potro trying to get after the Kokkinakis serve and gets a couple of points to make it 30-30.

Impressive response from the Aussie though, an unreturned serve followed by an ace to hold.

Compatriot and former pro Mark Philippoussis, part of the Kokkinakis team, takes a celebratory swig of water.

Australia's Thanasi Kokkinakis delivers an impressive winner in his match against Juan Martin del Potro.

Simple hold to 15 for Del Potro, a double fault aside.

Do these two just want to start the tie-break now?

That's a lovely response from Kerber, picking up Falconi's slice and slamming the ball past the American to hold her serve.

Still a few empty seats on Centre Court but there's a good crowd in to watch this match unfold.

The World Tonight

Virginia Wade says the Wimbledon sigh, or the groan of the crowd when a player makes a mistake, can be very unsettling.

Wade, who won the Wimbledon Ladies singles title in 1977, told Radio 4's The World Tonight she remembers one incident when she got a groan from the crowd, and she responded by saying "it's my fault, not yours, so what are you complaining about?"

Very easy hold to love for Kokkinakis.

This set is lagging at the moment. Who is going to grab the initiative?

Falconi wrong foots Kerber, taking a few steps towards the net and setting herself up for a drop volley, but she overcooks it with a flick of the wrist!

Kerber's starting to come forward too, nailing a winner down the line, and deuce comes up as Falconi lashes the ball out.

The German gets a break point but Falconi is stubborn. She sticks in the rally, drawing the error out of Kerber's backhand, and that'll be a hold.

Milos Raonic, last year's runner-up against Andy Murray, was given a tough test in the first set against Jan-Lennard Struff of Germany.

The world number seven eventually came through in a tie-breaker and has now taken an early break in the second set.

You can watch this match on Court One via this link.