And breeeeathe. Tension, drama, momentum swings, missed match points, injuries, trumpets... have I missed anything?
So let's do it again tomorrow, shall we? Join us from 12:00 BST for more Fed Cup fun.
Thanks for your company - cheerio.
'We'll do everything to get Katie ready'
Great Britain 1-1 Kazakhstan
More from GB captain Anne Keothavong: "It is still 1-1 and there is plenty to play for tomorrow.
"Katie knows there is still more to play tomorrow, but of course a loss like that is going to hurt her.
"But she knows she has got to come out again and we'll do everything possible to get her to her best and to be ready, we've got ice baths and trainers ready."
Sport can be cruel - Keothavong
Great Britain 1-1 Kazakhstan
Great Britain captain Anne Keothavong, speaking to BT Sport, on Katie Boulter's disappointing defeat: "She gave everything she had, that's all you can ask. At times she was struggling but she battled and put herself in that position. Sport can be cruel."
On Boulter's injury: "It could be a combination of a number of factors, pressure affects people in different ways, but she was able to come back out after having treatment in the changing room.
"She couldn't get over that slight hurdle, but credit to Putintseva, she's a fighter and made Katie play. You've got to give credit where credit is due."
Post update
Boulter 6-3 2-6 6-7 (6-8) Putintseva
So, after six long hours and two BPM-raising matches, it's all square after day one.
Tomorrow sees the two number ones - Jo Konta and Yulia Putintseva - go toe-to-toe first, with the second singles match following.
Whether that will be Katie Boulter or not playing for Britain, we don't yet know. Boulter picked up an injury at the start of the second set and will receive more treatment tonight.
Post update
Boulter 6-3 2-6 6-7 (6-8) Putintseva
If you weren't familiar with Yulia Putintseva before today, then that's the sort of fighting spirit for which she has become known for.
What a scrapper.
Post update
Boulter 6-3 2-6 6-7 (6-8) Putintseva
Kazakhstan's Yulia Putintseva after beating Katie Boulter in three dramatic sets: "My opponent was playing great, it was a good match, a good battle, a good crowd. I'm very happy to win I was fighting until the end and that's what helped me win."
Post update
Boulter 6-3 2-6 6-7 (6-8) Putintseva
While a distraught Boulter is comforted by Anne Keothavong, Yulia Putintseva is marching around the court celebrating like a WWE wrestler.
Roaring at the Kazakhs in the crowd, finger wagging, kissing her biceps like Hulk Hogan, the full works. Fair to say she is quite pleased...
Getty ImagesCopyright: Getty Images
Post update
Boulter 6-3 2-6 6-7 (6-8) Putintseva
Oh, poor Katie Boulter. She's in tears on his seat. Absolute heartbreaker.
Game, set and match Putintseva
Boulter 6-3 2-6 6-7 (6-8) Putintseva
Someone has just let off a lead balloon.
Extraordinary stuff from Yulia Putintseva, who watches Katie Boulter slap a tame forehand into the net.
The Kazakh fought off three match points to seal a remarkable win.
The Copper Box is in a state of shock.
Post update
Boulter 6-3 2-6 6-6 (6-7) Putintseva*
What. A. Shot.
A cracking forehand down the line from Putintseva! Now she has match point...
Post update
*Boulter 6-3 2-6 6-6 (6-6) Putintseva
Boulter can't convert that either - as much down to Putintseva's fight as anything she did wrong. Three match points spurned by the Brit...
Post update
Boulter 6-3 2-6 6-6 (6-5) Putintseva
Boulter's gone long. Now she has another chance on her own serve...
Post update
Boulter 6-3 2-6 6-6 (6-4) Putintseva*
A long rally ends in Putintseva hitting the net. And hitting the floor with her racquet.
Another match point for Boulter...
Post update
Boulter 6-3 2-6 6-6 (5-4) Putintseva*
What a winner from Boulter! Still on serve...
Post update
*Boulter 6-3 2-6 6-6 (4-4) Putintseva
The mini-break disappears down the drain again. Boulter hits the net as she tries to go down the line.
This. Is. So. Tense.
Post update
*Boulter 6-3 2-6 6-6 (4-3) Putintseva
Good first serve from Putintseva... but then Boulter rocks her with a deep forehand. The Kazakh can only respond by lumping one long.
Post update
Boulter 6-3 2-6 6-6 (3-3) Putintseva*
Putintseva goes down the middle with a second serve, a stretching Boulter cannot control her return...
Post update
Boulter 6-3 2-6 6-6 (3-2) Putintseva*
Boulter can press home this advantage here... she hits long. Again, she forgets about it and edges ahead. Still on serve...
Post update
Naomi Cavaday
Former professional tennis player on BBC Radio 5 live sports extra
It's one last push - but it feels like it has been one last push for the past half an hour.
Post update
*Boulter 6-3 2-6 6-6 (2-1) Putintseva
... never mind. Boulter dusts herself down and simply responds with a backhand winner down the line. Mini-break to the Brit...
Live Reporting
Jonathan Jurejko
All times stated are UK
Get involved
Getty ImagesCopyright: Getty Images
Latest PostGoodbye!
Great Britain 1-1 Kazakhstan
And breeeeathe. Tension, drama, momentum swings, missed match points, injuries, trumpets... have I missed anything?
So let's do it again tomorrow, shall we? Join us from 12:00 BST for more Fed Cup fun.
Thanks for your company - cheerio.
'We'll do everything to get Katie ready'
Great Britain 1-1 Kazakhstan
More from GB captain Anne Keothavong: "It is still 1-1 and there is plenty to play for tomorrow.
"Katie knows there is still more to play tomorrow, but of course a loss like that is going to hurt her.
"But she knows she has got to come out again and we'll do everything possible to get her to her best and to be ready, we've got ice baths and trainers ready."
Sport can be cruel - Keothavong
Great Britain 1-1 Kazakhstan
Great Britain captain Anne Keothavong, speaking to BT Sport, on Katie Boulter's disappointing defeat: "She gave everything she had, that's all you can ask. At times she was struggling but she battled and put herself in that position. Sport can be cruel."
On Boulter's injury: "It could be a combination of a number of factors, pressure affects people in different ways, but she was able to come back out after having treatment in the changing room.
"She couldn't get over that slight hurdle, but credit to Putintseva, she's a fighter and made Katie play. You've got to give credit where credit is due."
Post update
Boulter 6-3 2-6 6-7 (6-8) Putintseva
So, after six long hours and two BPM-raising matches, it's all square after day one.
Tomorrow sees the two number ones - Jo Konta and Yulia Putintseva - go toe-to-toe first, with the second singles match following.
Whether that will be Katie Boulter or not playing for Britain, we don't yet know. Boulter picked up an injury at the start of the second set and will receive more treatment tonight.
Post update
Boulter 6-3 2-6 6-7 (6-8) Putintseva
If you weren't familiar with Yulia Putintseva before today, then that's the sort of fighting spirit for which she has become known for.
What a scrapper.
Post update
Boulter 6-3 2-6 6-7 (6-8) Putintseva
Kazakhstan's Yulia Putintseva after beating Katie Boulter in three dramatic sets: "My opponent was playing great, it was a good match, a good battle, a good crowd. I'm very happy to win I was fighting until the end and that's what helped me win."
Post update
Boulter 6-3 2-6 6-7 (6-8) Putintseva
While a distraught Boulter is comforted by Anne Keothavong, Yulia Putintseva is marching around the court celebrating like a WWE wrestler.
Roaring at the Kazakhs in the crowd, finger wagging, kissing her biceps like Hulk Hogan, the full works. Fair to say she is quite pleased...
Post update
Boulter 6-3 2-6 6-7 (6-8) Putintseva
Oh, poor Katie Boulter. She's in tears on his seat. Absolute heartbreaker.
Game, set and match Putintseva
Boulter 6-3 2-6 6-7 (6-8) Putintseva
Someone has just let off a lead balloon.
Extraordinary stuff from Yulia Putintseva, who watches Katie Boulter slap a tame forehand into the net.
The Kazakh fought off three match points to seal a remarkable win.
The Copper Box is in a state of shock.
Post update
Boulter 6-3 2-6 6-6 (6-7) Putintseva*
What. A. Shot.
A cracking forehand down the line from Putintseva! Now she has match point...
Post update
*Boulter 6-3 2-6 6-6 (6-6) Putintseva
Boulter can't convert that either - as much down to Putintseva's fight as anything she did wrong. Three match points spurned by the Brit...
Post update
Boulter 6-3 2-6 6-6 (6-5) Putintseva
Boulter's gone long. Now she has another chance on her own serve...
Post update
Boulter 6-3 2-6 6-6 (6-4) Putintseva*
A long rally ends in Putintseva hitting the net. And hitting the floor with her racquet.
Another match point for Boulter...
Post update
Boulter 6-3 2-6 6-6 (5-4) Putintseva*
What a winner from Boulter! Still on serve...
Post update
*Boulter 6-3 2-6 6-6 (4-4) Putintseva
The mini-break disappears down the drain again. Boulter hits the net as she tries to go down the line.
This. Is. So. Tense.
Post update
*Boulter 6-3 2-6 6-6 (4-3) Putintseva
Good first serve from Putintseva... but then Boulter rocks her with a deep forehand. The Kazakh can only respond by lumping one long.
Post update
Boulter 6-3 2-6 6-6 (3-3) Putintseva*
Putintseva goes down the middle with a second serve, a stretching Boulter cannot control her return...
Post update
Boulter 6-3 2-6 6-6 (3-2) Putintseva*
Boulter can press home this advantage here... she hits long. Again, she forgets about it and edges ahead. Still on serve...
Post update
Naomi Cavaday
Former professional tennis player on BBC Radio 5 live sports extra
It's one last push - but it feels like it has been one last push for the past half an hour.
Post update
*Boulter 6-3 2-6 6-6 (2-1) Putintseva
... never mind. Boulter dusts herself down and simply responds with a backhand winner down the line. Mini-break to the Brit...