|Great Britain v Kazakhstan - Fed Cup World Group II play-off|
|Venue: Copper Box Arena, London Dates: 20-21 April|
|Coverage: Live commentary on BBC Radio 5 Live and live text commentary on BBC website|
Britain's Katie Boulter is "devastated" after missing three match points in a defeat that leaves her team's Fed Cup play-off with Kazakhstan level at 1-1.
The 22-year-old lost 6-3 2-6 7-6 (6-8) to Kazakh number one Yulia Putintseva after British number one Johanna Konta had won the opening singles rubber.
Konta needed to block out a noisy band to beat Zarina Diyas 4-6 6-3 6-2.
Britain are seeking promotion to World Group II for the first time in 26 years in the best-of-five tie in London.
The two reverse singles and a doubles match are taking place from 12:00 BST on Sunday.
"I put everything out there," Boulter said. "It's part of sport though - you win some and you lose some.
"It will be replaying in my head for a long time, that's for sure."
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Heartbreak for Boulter after 'cruel' defeat
Katie Boulter's Fed Cup debut in February was impressive and she started off in much the same way here at London's Copper Box Arena.
The world number 86 was the underdog against world number 38 Putintseva but she held her nerve to fight off deuce at 3-3 in the first set, before breaking in the following game.
That brought a reaction from the home crowd and Boulter used every opportunity to work them up - roaring in celebration after firing a backhand down the line during a service hold to move 5-3 up.
She was fearless in her play and full of confidence after breaking for a second time and taking the first set - silencing the Kazakh trumpet-and-trombone band and taking advantage of an out-of-sorts Putintseva.
The Kazakh number one re-grouped to break twice to go 2-1 up in the second set and her pressure took its toll on Boulter, who took a lengthy medical time-out.
Putintseva marched on to claim a comfortable second set but Boulter's resurgence returned as she won the opening four games in the decider and showed no signs of injury.
The Briton was pegged back, though, with Putintseva using all her experience and skill to force a tie-break after breaking back twice and holding off match point in the final game of the third set.
Boulter had a further two match points saved in the tie-break - at 6-4 and 6-5 on her serve - as Putintseva's risky baseline strokes paid off.
The British number two was comforted in her chair by captain Keothavong after she impressed yet again on the Fed Cup stage but to no avail this time.
"She gave everything she had, that's all you can ask," Keothavong said.
"At times she was struggling but she battled and put herself in that position. Sport can be cruel."
Boulter will have to recover quickly as she is scheduled to take on Diyas in what could be the deciding singles rubber on Sunday.
"I am devastated, clearly," Boulter said.
"I will be doing my absolute best to recover tonight and I am sure my body will be fine. I was just struggling a little bit."
Konta adapts to challenge of Diyas and trombone
Konta got Britain off to a winning start with a spirited performance against Kazakh world number 107 Diyas.
The Briton was up against it from the off, though - battling to block out constant drumming, trumpet-playing and chants from the travelling Kazakh fans.
An antagonistic tune was played when Konta's volley flew over the baseline as she fell 2-0 down in the opening set and the Briton looked distracted, glancing over at the band seconds before being broken again at 4-1 down.
"When you first hear the trombone it takes some time to get used to it," Konta said. "I was in two minds on it because I thought 'he is actually really good!'
"It is a tricky situation for any player to face but you get more resilient as the match goes on. You adapt and find a way to deal with the challenges."
Konta found the response when she smashed her first ace of the match at 5-1 down and went on to claim a comfortable service hold that seemed to spur her and the home crowd on.
She won the next three games and, despite losing the first set, raced to a commanding 5-0 lead in the second.
Diyas, who had lost just one of her 14 previous singles matches in the Fed Cup, responded with resilience of her own - clawing it back to 5-3 before holding off five set points.
But a key moment came when Konta saved two break points in her opening service game of the third set, skipping off at the changeover with a fist-pump towards the crowd.
"I don't think I got bogged down by things too much. I was enjoying being out there and trying to find a way," Konta said.
"I found my way a little bit more in terms of when to mix it up. I definitely have been trying to add some more variety to my game in the last few months.
"It is more about making what I do well more effective. I am clear of the kind of player I am. But people are used to playing me. I'm not a fresh chick any more."
The Briton quickly raced into a 4-1 lead in the decider, before Diyas called for a medical timeout for a shoulder issue.
That small break in play did little to quieten the home crowd and Konta responded to the roars of support to break back immediately after dropping serve at 4-2.
It took Konta two hours and 38 minutes to complete the comeback but tomorrow's opponent Putintseva won't have fared any better from her gruelling match with Boulter.
BBC tennis correspondent Russell Fuller
Katie Boulter's race looked run at the end of the second set as what appeared to be a back problem took its toll.
She wrestled the initiative back with a breathtaking start to the decider, but Putintseva's defence, fight and willpower were truly exceptional.
Boulter had two glorious early chances to take control of the tiebreak, but was reeled in once again by the irrepressible Putintseva, who celebrated by kissing her biceps.
Earlier, Johanna Konta took a long time to impose herself on Zarina Diyas, but to her credit, was a reasonably comfortable winner in the end.
Ten successive Fed Cup singles wins is a fine achievement - and as Britain's number one she will get the chance to lead from the front in Sunday's singles.
And silence the trombonist from Kazakhstan, who greeted Konta's early errors with an ironic and sorrowful lament.