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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) 0-0 Kontaveit
The serve works a treat when it truly matters!
Chills. The Arthur Ashe crowd rises to their feet.
Something special is happening in New York - but there's a long way still to go.
Jonathan Jurejko
BBC Sport at Flushing Meadows
"Let's go Serena!" - followed by three claps - rings out around Ashe.
The crowd know every bit of noise and encouragement they can give to their hero might prove vital at this perhaps pivotal juncture.
*Williams 6-6 (5-4) Kontaveit
Laura Robson
Former British number one on BBC Radio 5 Live
Serena is picking up the energy, the intensity, and she looks so focussed
*Williams 6-6 (5-4) Kontaveit
It's first bllod to Serena Williams in the tie-break as Kontaveit slices an attempted drop shot into the net.
Williams had read it though and was already there.
She'll serve with a 5-4 lead. The first set is within reach once again.
Williams 6-6 (4-3) Kontaveit*
Powerful hitting from Kontaveit. She draws the error from Serena Williams for a 3-2 lead.
The American responds with a brutal backhand winner and a sweet first serve.
*Williams 6-6 Kontaveit
Laura Robson
Former British number one on BBC Radio 5 Live
It has been physical - much longer rallies than on Monday night.
This is vintage Serena serving tonight.
Williams 6-6 (2-1) Kontaveit*
An excellent backhand from Serena Williams, followed by a shake of the fist. She does the business with her first couple of serves to go 2-1 up.
Williams 6-6 Kontaveit
We're heading for a tie-break!
Serena Williams uses her serve to get out of trouble before finishing the game with a pinpoint forehand.
*Williams 5-6 Kontaveit
Credit to Anett Kontaveit, she has not been overawed by the atmosphere on Arthur Ashe and is doing a decent job of keeping the crowd quiet just when it feels as though Serena Williams is gaining momentum.
The spectators fall quiet as Kontaveit levels at 30-30.
*Williams 5-6 Kontaveit
Now it's the world number two who can smell the first set.
Can Serena Williams hold her nerve and take us to a tie-break?
*Williams 5-6 Kontaveit
This is a good response from Serena Williams to that setback, with the first set in her grasp. The American makes it to 30-30, but Kontaveit ends her hopes of an immediate response with a smart drop shot.
Williams 5-5 Kontaveit*
Laura Robson
Former British number one on BBC Radio 5 Live
You do feel like this first set is way more important for Serena than for Kontaveit. The energy levels - you feel like she is using everything in the tank.
Can she sustain that? I hope so.
Williams 5-5 Kontaveit*
Gigi Salmon
BBC Sport tennis commentator
Rennae Stubbs has made Serena Williams play practice sets and I think this has helped.
Normally she stays in her bubble but Stubbs insisted because it is important to get as much match practice as possible.
Jonathan Jurejko
BBC Sport at Flushing Meadows
The fuse has been lit!
Williams finally gets the break which has threatened and Ashe erupts in celebration.
Fans leap to the feet all over the stadium as the decibel level darts north.
But wait, not quite time to get the party started...
Williams 5-5 Kontaveit*
Wow. A double fault from Serena Williams, who concedes the break and we're back level at 5-5!
*Williams 5-4 Kontaveit
Great work from Anett Kontaveit. She forces Williams into the net and it will be three break points for the world number two.
*Williams 5-4 Kontaveit
A couple of misses from Serena Williams see Anett Kontaveit move out to 0-30.
*Williams 5-4 Kontaveit
A huge game for Serena Williams here.
The chance to go one set up against the second seed.
Kyrgios 7-6 (7-3) 6-4 4-6 6-4 Bonzi
Nick Kyrgios is through to the third round!
It's been a typically fiery encounter (on his side) with Kyrgios repeatedly berating those in his box.
Frenchman Benjamin Bonzi was undeterred by the Australian's outbursts and stepped up his level in the last two sets.
Kyrgios faced three break points at 4-4 in the fourth set, but saved them all and then broke himself, roaring to the New York sky in celebration at his victory.
*Williams 5-4 Kontaveit
Laura Robson
Former British number one on BBC Radio 5 Live
Serena is playing with so much aggression, she can't take any control back in the rally. How clever is this variation from Serena.