A "devastated" Katie Boulter vowed to pick herself up and help Great Britain try to reach World Group II after a dramatic first day of Fed Cup action at London's Copper Box.
After Johanna Konta recovered from a dreadful start to defeat Kazakhstan number two Zarina Diyas 4-6 6-3 6-2, Boulter led 4-0 in the deciding set and held three match points against Yulia Putintseva but lost 3-6 6-2 7-6 (6) to leave the match tied at 1-1 going into the final day.
While Putintseva, one of the grittiest competitors on tour, celebrated exuberantly in front of the noisy band of Kazakh supporters, a tearful Boulter had to be consoled on her chair.
Speaking later, she said: "I am devastated, clearly. I expect her to play well on the big points, that's why she's ranked where she is. She's a competitor, she's got a great game.
"Of course it's tough not to come through the match points and it's going to be replaying in my head for sure for a while, but I'm going to get over it and I'm going to get ready for tomorrow and bring some game."
Boulter is ranked 48 places lower than Putintseva at 86 in the world but played well above that to power her way to the opening set before appearing to suffer an injury at the start of the second.
She looked comfortable again at the start of the decider and raced into a 4-0 lead but was unable to serve out the match at 5-3 before Putintseva saved her first match point at 5-6 after a tremendous rally.
Boulter then led 6-4 in the tie-break but again just could not break the Kazakh down, and when Putintseva's first chance came, she grabbed it.
Boulter was cagey about the nature of her injury, saying it was a "general" issue, but she is confident she will be fit to play the fourth rubber on Sunday against Diyas.
Asked if she tweaked something, she said: "Not necessarily. I was just struggling a little bit physically, but I've got a great team around me and I'm sure I'll be ready to go tomorrow."
If Boulter is not fit, Keothavong would have to call on either out-of-form Heather Watson or the inexperienced Harriet Dart or Katie Swan.
The first match on Sunday, and one that could prove decisive, pits Putintseva against Konta, who allowed nerves and the crowd to get to her early on against 107th-ranked Diyas as she lost five of the first six games.
Konta, Keothavong and the wider British team all complained to the officials about the conduct of the Kazakh fans – whose 250-strong group included two drummers and a man alternating between playing the trombone and trumpet.
Keothavong said: "There were a few issues with some Kazakh fans making noises right before she (Konta) hit the ball, which I could hear clearly. We expect lots of noise but when someone's trying to deliberately put a player off I don't think that's really called for."
One shout led to Konta fluffing a volley on set point to Diyas in the opener but by that point she had already begun to play better and ultimately she was too powerful.
Konta said: "Obviously tennis is quite a traditional sport in the way spectators are and Fed Cup is very different to that so, while it makes it very exciting and enjoyable, it's just a different situation.
"You need to find your feet as quick as you can. It does shock you when you first hear that drum or trombone."
Keothavong remains confident her team can emerge victorious despite the blow of not taking a 2-0 lead as they bid to reach the World Group for the first time since 1993.
"We came into this weekend expecting a tough challenge from the Kazakhs. We certainly got that today but we're in it to win it," she said. "The players know what they have to do."
Kazakh captain Dias Doskarayev shrugged off the suggestion Britain will find it hard to pick themselves up.
"These players are experienced," he said. "Of course it kind of gives us a little bit of momentum but not a huge amount. Our chances on paper and in fact are 50-50."
