Gigi Salmon
BBC Radio 5 Live

Great ball striking from both players but it's the greater consistency from Naomi Osaka.

The errors are starting to drop heavily now from Coco. She's rushing her serves too - another double-fault.

40-15. Two break points.

Coco reads the serve and her return is a good one but Osaka feeds it down the line and the teenager pulls a backhand into the net.

The American shows her frustrations as another big return is followed up by an unforced error.

Image source, Getty

Sulaimon Adelekan: It's past 12 am in Lagos, Nigeria. Up and on the BBC website. Rooting for Coco.

Nerves of steel. Osaka saves two break points - slamming a forehand onto the sidelines. She claws it back to deuce with a stunning winner down the line.

Wow.

Osaka looks up to the sky as a sliced backhand causes her problems. She then finds herself three break points down as she struggles to sort her feet out when Coco crashes back a return.

Odds stacked against Coco then?

Jamie Murray and Bethanie Mattek-Sands breeze to the first set in 28 minutes - just the single break point needed for the British-American pair. Easy does it...

Double-fault.

Oh dear...

Coco skews a forehand into the net then double-faults. 30-0... She flashes her racquet through the air, practicing the motion before dishing up a pacey second serve.

But Osaka picks up a brilliant volley and brings up two break points.

An intense opening set. There were five breaks of serve but you sensed Coco was struggling a little more - only 46% of her first serve points were won.

Osaka was way up on winners too - 15 to Coco's four.

Much better. Osaka moves into the court and slams a backhand winner. Set point...

She takes it! Coco's backhand falls short.

Osaka pulls a backhand into the net - fist pump from Coco, wry smile from the defending champ.

Double-fault... Time violation warning... then an unreturned serve. Coco's unforced error levels it at 30-30.

Definitely a few nerves from Osaka though.

For the third time in the set, Osaka breaks. Coco slumps one into the net. The Japanese is serving for the set.

A murmuring of groans ripple around Ashe as Coco double-faults. Osaka senses a time to pounce and smashes a backhand winner.

She brings up two break points.

Thoughts so far? A corker.

Image source, Getty Images

Jamie Murray and mixed doubles partner Bethanie Mattek-Sands have broken in the opening set of their first-round match against John Peers and Zhang Shaui.

They lead 4-2 in the first set.

Yep, you guessed it. Coco breaks back.

Osaka works the point well, pushing the teenager wider and wider to set up the winner but she thumps it into the cords.

Osaka responds to an error by serving up a 114 mph ace. She skews another backhand but again, a powerful serve down the T draws her level. 30-30.

But it's break point when she goes wide.

This is already a brilliant match!

Coco moves into the net and pushes a forehand into the corner. One break point saved.

A second one? Nope. Coco pulls a backhand wide. She looks annoyed too.

Image source, Getty