The first is saved as Osaka hits her forehand into the net, but Azarenka then pulls her angled backhand wide.

The former US Open champ gets the crucial break.

A first double fault for the elder stateswoman.

Then two more errors.

Triple break point!!

Brilliant from Osaka in this game.

Two big serves and then goes toe-to-toe on a rally which ends with a winner.

Another ace - her fourth - and it's game.

Quick and easy.

Image source, Reuters

Azarenka takes to her chair, closes her eyes and meditates.

Calm before she re-enters the storm.

Another Osaka error - her 16th - and it's game Azarenka.

The Belarus player, who defeated Serena Williams in the last four, tries to put Osaka on that string again.

30-0 before she troubles the netting with an approach shot.

Service resumes with an ace.

Naomi Cavaday
BBC Radio 5 Live tennis commentator

Osaka has really pulled herself together, she is very good at coming back from a set down.

Punishing from Osaka at the back of the court - tossing Azarenka from side to side before launching a winner from her barrel.

The Japanese player holds, emphatically, with an ace.

That break at the chair appears to have helped Azarenka retune her radar - a forehand winner clips the line for 0-15.

But it also seems to have helped Osaka - an ace then a cracking flat angled winner.

Azarenka makes another - on her forehand - and is broken by Osaka.

How big could that be in this match?

Image source, reu

Naomi Cavaday
BBC Radio 5 Live tennis commentator

It's flawless from Azarenka. If you are part of her coaching camp, you are nodding and clapping on the inside.

Osaka plays Azarenka at her own game with a deep forehand return down the line which her opponent scrambles to get even a racquet frame on.

Now then...the Belarusian makes an error.

Break back point!

The fierce groundstrokes have been a joy to watch, but Azarenka produces a sliced drop which is judged to perfection.

30-15.

Naomi Cavaday
BBC Radio 5 Live tennis commentator

Azarenka has not allowed Osaka to strike anything, I've counted four that she's allowed her to get a good clean strike on.

Osaka has got to dig her heels in now. She is still looking a bit negative on court.

She takes the second with a double hander that lands deep and one that Osaka can only waft her racquet at.

This is painful for fans of the Japanese player.

Azarenka looks great from the baseline and is not scared of coming to the net - slapping a forehand winner at the net for 15-30.

Error from Osaka and it's two break points.

History repeating?

The former number one holds to 30 with a punchy forehand winner on the frontfoot.

Azarenka, a two-time runner-up here, won the first set in a Flushing Meadows singles final for the first time. BTW she won 94% of points on her first serve - 16 from 17.

Incredible.

The gods are also smiling down on her as her groundstroke bounces twice off the cord and falls over on to Osaka's side.

40-30... should get over the line here. But then Azarenka produces a truly wondrous double-handed backhand winner.

Deuce.

The Cincy champion then brings up break point and converts with another stunning winner down the line.

If you want to see a perfect Grand Slam set, rewatch that one.

Osaka is panicking a bit. She's looking at her camp after every point. She doesn't really know how to tackle this from Azarenka.

Image source, gett