What on earth is going on. Sakkari is rocking. Another error concedes the break and Raducanu lands the first blow of the second set.

Sakkari is still struggling to get herself firing on serve.

Boom. Raducanu swats a backhand return from a second serve into the corner for 30-15. There's no let up from there - two break points!

Nope. Raducanu is still refusing to give anything away and wraps up the game with little fuss. Time to put the pressure back on Sakkari.

Dom Breslin: You wouldn’t know it’s her 1st Night Session in the biggest Stadium in the sport. Flawless set of Tennis from Emma Raducanu - has got Sakkari rattled. 1 more for a Grand Slam Final.

Ayo Obit: Emma Raducanu has not dropped a single set in her 8 matches (incl qualifiers) so far in US Open and she has just dismantled Sakkari 6-1 for a 17th consecutive set win! Is it OK to go and sleep now?

Steve: What a player. We are very lucky to have her. So mentally strong.

Superb. Emma Raducanu closes in on the net, forcing Sakkari back before a deft volley kills the point for 30-15.

A first double fault of the match from the Briton gives Sakkari hope, though.

A clean, swift hold to love for Maria Sakkari in her opening service game of the second set. The Greek will surely have more to say in this second set.

Naomi Broady
British player on BBC Radio 5 Live

This level is what we have seen from Emma Raducanu throughout the tournament - I am completely forgetting about rankings and experience, and I am absolutely not surprised by the scoreline in the first set.

You're glad you stayed up now, right?

The 18-year-old Emma Raducanu is one set away from the US Open final.

Emma Raducanu just keeps on getting better, and better, and better.

This is ridiculous consistency from Raducanu. Two set points.

Naomi Broady
British player on BBC Radio 5 Live

She is so solid, Emma Raducanu, she matches pace of her opponent so well. Her statistics over the last few matches have been incredible.

Raducanu steps up to serve out the opening set.

A double fault - Sakkari's third of the match already - gives Raducanu a look in at 40-30, but the 17th seed is grateful to see her opponent miss with just her sixth unforced error and a first game is added to her side of the scoreboard.

Right then, Maria Sakkari to serve to stay in the first set. If we can't believe it, imagine how she must feel right now as she too attempts to reach her first Grand Slam final.

An ace is backed up by a fine forehand as the Greek edges ahead.

Image source, Getty Images

Gigi Salmon
BBC Radio 5 Live tennis commentator

This is unbelievable what we are witnessing.

Image source, Getty Images

David Law
Commentator on BBC Radio 5 Live

I am sitting here shaking my head in disbelief at the level, the composure, the poise, the confidence and ambition she is playing with.

No, that's not a typo above, and you're not hallucinating due to lack of sleep.

Emma Raducanu is 5-0 to the good against world number 18 Maria Sakkari in the semi-finals of the US Open.

Absolutely insane.

A forehand is well overhit from Sakkari as another game swiftly gets away from her.

That's all about Raducanu, though. A poor drop shot isn't punished by the Greek, and the British teenager is there to ask one more question of Sakkari - who pops a volley wide of the mark.

Naomi Broady
British player on BBC Radio 5 Live

Sakkari has not got time to think about what shot she wants to play and how she is going to play it.

Wow. Emma Raducanu just won't give Maria Sakkari an inch. The Briton puts away a backhand for another break point.

Ouch. That tells you exactly where Sakkari's mind is at. A double fault concedes the double break. Raducanu is in dreamland once again!