What a rally! The players draw level at 12 winners apiece and Serena Williams applauds Anett Kontaveit for this latest one as a forehand beats the American.

But Williams won't go away. She doesn't want her journey to end tonight.

She sets up another chance to make the first breakthrough and this time Kontaveit misses!

The biggest noise of the night so far. Williams will serve for the first set.

So good. Absolutely no issues with movement for Serena Williams, one month from her 41st birthday, as she makes it to a drop shot and flicks a forehand winner into the back of the court.

A good hold to 15. And now she can set about applying more pressure on Kontaveit's serve.

Image source, Getty Images

More spectators filter in as the players recover from that marathon game, filling up a few more of the remaining empty blue seats.

It's over to Serena Williams to once again try and level up this opening set.

Jonathan Jurejko
BBC Sport at Flushing Meadows

This is more like it! Williams pushing her foot on the pedal in search of a break has got the adrenalin of the revellers going.

British umpire Alison Hughes regularly has to tell those who are being over-exuberant (at best) - or rude to Kontaveit (at worst) - to keep the noise down and not cheer the Estonian’s missed first serves.

When Kontaveit does hit a winner it feels like we’re in MOMA. An eerie silence with just the sound of the air con pumping.

Laura Robson
Former British number one on BBC Radio 5 Live

This is the best we have seen Serena move tonight - and mixing up the forehand. But good luck with telling the crowd to be quiet during points.

Kontaveit is getting bigger with her groundstrokes and that to me spells pressure, as she is trying to go for everything. In so many ways this must be easier for Serena to play someone ranked so much higher.

A third break point for Serena Williams...

But silence falls as she slips soon after, with Kontaveit knocking the ball into an open court.

Finally, the second seed is able to close an epic game out for a 4-3 lead. That was quality.

Oh yes! Some superb defensive work from Serena Williams is followed by a whipped cross-court winner as the home favourite sets up another break point.

But Kontaveit battles back to bring up a sixth deuce as this game passes the 10-minute mark. Great drama.

Kontaveit fights back and makes it to game point despite the whole stadium, bar her own team, seemingly wanting her to falter.

Once again, though, she can't escape. This feels like a massive game.

Jonathan Jurejko
BBC Sport at Flushing Meadows

Feels like an odd atmosphere on Ashe. At least from up in the gods where I am.

Not quite as celebratory, raucous or expectant as Monday night.

Maybe seeing [2] next to Kontaveit’s name has spooked a few of the more casual fans.

Kontaveit is first to blink in a brilliant rally as she's hauled back to deuce.

The noise! The excitement among the crowd grows even further as Williams reaches break point.

A double fault from Kontaveit gives Serena Williams hope of an opportunity at 15-30 and, though Kontaveit manages to swing the game in her favour, the American gets lucky as a shot drops over the net for deuce.

The crowd don't care how she wins the points, of course.

David Law
Commentator on BBC Radio 5 Live

Kyrgios has been ranting and talking between every point, Bonzi is just letting Kyrgios capitulate. Kyrgios is looking stressed and Bonzi could take him all the way.

Laura Robson
Former British number one on BBC Radio 5 Live

It is tough to know where I would put Williams. I feel Kontaveit is not playing at her ranking either. But would Williams be able to play like this without a crowd and without the whole experience?

There was a delayed 'Come on' from Serena as she wasn't sure if that last shot went in.

Kontaveit silences the crowd as she connects beautifully with a forehand on the rise, but Williams finishes things off with a forehand of her own to restore parity at 3-3.

Wonderful hitting from Serena Williams. She can once again rely on her effortless serve to move ahead, before the American pops away a devastating backhand winner.

Another excellent serve sets her up for a forehand on the run, but a double fault halts her progress.

A couple of missed forehands from Serena Williams and Anett Kontaveit is soon on her way to another hold of serve. No trouble for the Estonian here.

Laura Robson
Former British number one on BBC Radio 5 Live

Kontaveit is deciding to go all out and keep Serena guessing.

But it is Kontaveit's forehand side that can break down a lot more, she can go to pieces in a match and that's why she has not achieved more in a slam.

Jonathan Jurejko
BBC Sport at Flushing Meadows

The stars always come out at Ashe and always come out for Serena Williams.

Zendaya - apparently filming a new tennis film - is one of the first celebs to be picked out by the cameras.

Gotta do your research!

Serena Williams' serve is firing tonight. It helps her to safety from break point down to the delight of the Arthur Ashe crowd.

This has been a great start. On we go on serve!

An ace gets Serena Williams up and running and, after she has to pause to tie her laces, she pulls level again at 30-30.

Shot! Kontaveit gets hold of a return to reach break point.