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LIVE: Serena Williams beats Anett Kontaveit 7-6 (7-4) 2-6 6-2 to reach third round
Victory prolongs American's farewell before impending retirement
LIVE: Briton Jack Draper faces Canadian sixth seed Felix Auger-Aliassime in second round
Earlier: Andy Murray beats Emilio Nava 5-7 6-3 6-1 6-0 to reach third round
Britain's Harriet Dart loses 6-4 6-0 to Hungary's Dalma Galfi
Britain's Joe Salisbury and American Rajeev Ram make winning start to their men's doubles title defence
Williams 7-6 (7-4) 1-4 Kontaveit*
Laura Robson
Former British number one on BBC Radio 5 Live
You can hear how hard Serena is trying. Hands on hips looking up the crowd, looking up at her box. 'What more can I do?'
I think she is just in her own head slightly at the moment.
Image source, Getty ImagesWilliams 7-6 (7-4) 1-4 Kontaveit*
I mean, the crowd may be reluctant to acknowledge it, but that's some comeback from Kontaveit to turn that game in her favour and restore her three-game advantage in this must-win set.
Just when Williams had the chance to move within striking distance.
*Williams 7-6 (7-4) 1-3 Kontaveit
Serena Williams once again is able to call on her serve as an ace gets her out of trouble, and another excellent first serve denies Kontaveit moments later.
Will it be third-time lucky for Kontaveit? She'll have another shot...
*Williams 7-6 (7-4) 1-3 Kontaveit
Awesome effort from Kontaveit. A double fault from Serena Williams brings her opponent into play in what had been an impressive service game, and out of nowhere the second seed is able to reach deuce.
It could get even better for her now. A wonderful backhand fizzes down the line for break point.
*Williams 7-6 (7-4) 1-3 Kontaveit
Serena Williams has found some extra power. A couple of aces take her to 40-0.
*Williams 7-6 (7-4) 1-3 Kontaveit
Laura Robson
Former British number one on BBC Radio 5 Live
The crowd had gone silent a well. This is where they need to be picking her up and giving her the energy. They can do a lot of work.
What a strange game from Kontaveit - she had worked so hard to get the double break.
Draper v Auger-Aliassime
After a long wait, it's finally time for Britain's rising star Jack Draper to take to the Louis Armstrong court for his second-round clash with Felix Auger-Aliassime.
Last year, Auger-Aliassime became the first Canadian men’s singles semi-finalist in US Open history, but he won't have it easy against world number 53 Draper, who got his first win over a top 10 player earlier this month in beating Stefanos Tsitsipas in Montreal.
Image source, Getty Images*Williams 7-6 (7-4) 1-3 Kontaveit
Now then.
Kontaveit, in control of the set, tightens up. Another error and Serena Williams has one break back!
Williams 7-6 (7-4) 0-3 Kontaveit*
A terribly timed double fault from Anett Kontaveit.
Break point!
Jonathan Jurejko
BBC Sport at Flushing Meadows
Gladys Knight is back in the house.
Of course, the soul legend is cheering on Serena and mouths 'GOAT' as she points towards her favourite.
Some might say Williams is the Best Thing That Ever Happened (To Tennis)...
Williams 7-6 (7-4) 0-3 Kontaveit*
In what feels like the blink of an eye Serena Williams has gone from taking the first set to falling a double break down in the second.
She'll keep fighting in this set though and she's up to 30-30 on the Kontaveit serve.
Williams 7-6 (7-4) 0-3 Kontaveit*
Laura Robson
Former British number one on BBC Radio 5 Live
I think Serena's legs have just left her slightly.
Williams 7-6 (7-4) 0-3 Kontaveit*
Serena Williams is becoming a lot more vocal as she tries to get herself up to speed with Kontaveit in this second set.
But Kontaveit is on fire here.
An incredible start to the second set from the world number two continues as she lets rip with a forehand to clinch a first break point.
Image source, Getty Images*Williams 7-6 (7-4) 0-2 Kontaveit
'Come on' shouts Serena Williams as she follows up a wide serve with a forehand into the opposite corner. Lovely play.
But Kontaveit keeps the crowd in check as she steps up to wallop a two-handed backhand, before a stunning return takes her to deuce.
Jonathan Jurejko
BBC Sport at Flushing Meadows
Incredible.
Who would ever write off Serena Williams? Like, ever. In anything.
Whatever happens from here, Williams will be eternally proud of this performance.
She is ranked 605th. She has played five matches in the past 14 months. She turns 41 next month.
And she is beating the world number two. Drink that in.
*Williams 7-6 (7-4) 0-2 Kontaveit
Anett Kontaveit scorches the baseline with a forehand after it appeared Serena Williams had taken charge of the point as she chases a response.
There's no way back for now. An ace wraps up a love hold to consolidate that early break.
Williams 7-6 (7-4) 0-1 Kontaveit*
Laura Robson
Former British number one on BBC Radio 5 Live
You could almost expect an early break of serve. Serena gave everything in the first set, and it happens to everyone, not just Serena.
Williams 7-6 (7-4) 0-1 Kontaveit*
What a response from Kontaveit.
Three break points.
She only needs the first.
The celebrations are over for now on Arthur Ashe. The world number two means business.
Image source, Getty Images*Williams 7-6 (7-4) 0-0 Kontaveit
Serena Williams has lost just three of her previous 103 US Open matches in which she won the opening set.
Anett Kontaveit is going to have to be at her very best to turn this around.
On we go with set two.
Williams 7-6 (7-4) 0-0 Kontaveit
Laura Robson
Former British number one on BBC Radio 5 Live
Kontaveit hit the panic button. She was the one that was attacking and then decided one shot too early to change it up.
This crowd go mental.