Coco Vanderweghe is wandering around the court like it was named after her rather than Rod Laver.

She looks like the Grand Slam veteran rather than Williams. She closes out the game with a gossamer soft drop volley.

She had never been beyond the third round of a Grand Slam before this week, but Coco Vandeweghe is just a set from her first final.

Coco has struck gold just when she needed it.

Another stand and deliver return winner and she has four set points at 6-2 up.

Crazy days. Coco takes two points against the head, her backhand coming to the party, and is a mini-break to the good as the ball head up her end of the court.

A deft volley from the younger American, sucking all the venom out of Venus forehand and dribbling over a lethal dropper and Coco takes on isotonic well clear.

5 live's Cat Archer: "Big cheers for a Venus Williams mini break in the Melbourne Park garden."

Image source, BBC Sport

Venue stretches out wide and finds an angle from off the protractor to strike right back. Mini break redeemed. 1-1.

Boff! What a return! Coco's advance to the net turns to a trudge as Venus punches a backhand down a corridor of space. 2-1 Venus.

Coco reads the Venus second serve like a book and swat a backhand winner across court to take the early mini break 1-0 Coco.

An ace right into the apex of the service box to open up from Coco. Venus Williams gave it a long look, but that ball's footprint was just about perfect. 

Coco couldn't have placed it better if she had crawled under the net on all fours and put it there herself.

Venus is grunting with exertion as she is made to scurry and chase, but Coco puts her out of her misery with an overdose of forehand power. 

Clear Main Street, we are into a shoot-out.

Coco Vandeweghe with no margin for error as she serves to stay in the set.

But that is a vice-like hold to love. Coco 28-30 Venus on total points won so far and it feels that close.

Anyone's set, anyone's guess.

Coco Vandeweghe has a patsy second serve on toast, smiting a mighty forehand for 15-15.

But the New Yorker is rueful after misjuding a deep bounce in the next rally, and then positively seething at her own backhand in the following exchange as she slips to 40-15.

The opposite wing is the stronger. A whopper of a forehand brings up 40-30, but she is a smidge wide and the video review allows Venus to escape to the changeover stool. 

A comfier spot than the deuce alternative.

That was a statement of intent as service games go.

A hold to love - full of string-stretching power - from Coco Vandeweghe.

Venus Williams still motoring on serve. 

Coco Vandeweghe got closer in that game, planting her feet and slinging the racquet head through the ball, but she is denied the consistent platform from which to force a break chance.

Venus Williams scrapes a superb winner off her shoelaces, but that is not enough to throw a spanner in Coco Vandeweghe's spokes.

Evenly poised - as even as it could be in fact - as we head into the business end of the opening set. 

Venus Williams claims a second successive love service game. After that inexplicably twitchy start in the very first game, her big-match big-arena experience is starting to show.

Coco Vandeweghe pumps down a sweet-as-a-nut ace for 30-0. The 25-year-old, daughter of an Olympic swimmer, granddaughter of a former Miss America, gets into a little strife at 30-30.

But Venus strays long and she is through unscathed. Twenty-two minutes on the clock, just four games on the board.

Venus Williams has located the mojo that was MIA in her first service game.

A love hold as Coco Vandeweghe fails to lay a glove on her. 

You get the feeling that this is just one wrinkle in a match that will twist and turn more than the big flume.

Image source, EPA

My, my, my.

Venus Williams cracks a lovely stretching forehand back across court for a clean winner and Coco Vandeweghe can only turn on her heels and prepare to serve at break point down.

The younger American thinks she has landed a service winner, but her first attempt has caught a sniff of net cord. Let. 'Second' first serve is a duffer. The second serve is wide of the whitewash by the width of a string.

Double fault and even stevens.

Venus Williams attempts to change the tide as she comes to the net at 30-0 down.

Her volleying is a little Bambi-on-ice. Uncertain long limbs prodding at fresh air, but a lucky break off the top of the net cord gives her her first point in the game.

Coco slaps down the first ace of the match to move 40-30 up, but Venus' racquet arm is loosening off.

A gunslinger forehand - shot inside-out off the hip - takes the game to deuce.

At the fourth time of asking, Venus Williams' faulty, spluttering forehand breaks down to hand Vandeweghe a nitro boost start to the semi-final.

Image source, getty