Johanna Konta showed plenty of character as she fought back from a set down to claim victory in the opening rubber of Great Britain's Fed Cup showdown against Kazakhstan but day one ended with the tie level.
British number one Konta defeated Zarina Diyas 4-6 6-3 6-2 to earn her tenth successive win in the Fed Cup singles and put the hosts 1-0 up in the World Group II play-off encounter.
But it was heartbreak for Katie Boulter in the second rubber as she lost a tie break in the third set to go down to Yulia Putintseva 6-3 2-6 6-7 (6-8) as the Kazakh number one levelled the tie.
The pressure will now be on the reverse singles and doubles rubber on Sunday – and after coming through her tough examination, Konta admitted she had to dig deep to get the win.
“I’m obviously very happy to have gotten that first rubber under our belt for the team,” she said. “More than anything I was quite proud of my perfromance out there, it was quite tough.
“At the beginning she was playing very well and I really had to find the level and the game to be able to compete against her and come through in the end.
“So I was just happy I was able to do that. It’s hard to put into words [what the atmosphere was like] because I don’t think anything really justifies what it’s like.
“You have to be there on court and feel it. They’re super loud, they’re super supportive, they’re really with you for every single point win or lose. They’re living the whole match with you.”
Britain are seeking promotion to the elite World Group for the first time in 26 years in the best-of-five tie in London and they got off to a perfect start thanks to Konta’s gritty performance.
The 27-year-old found herself 5-1 down in the first set before rallying to only lose it 6-4. She built on that momentum to clinch the second set 6-3 as she began to take control.
And the home favourite stamped her authority on the match in the deciding set, racing into a 4-1 lead and eventually prevailing 6-2 to continue her impressive Fed Cup winning run.
All eyes in the Copper Box Arena then turned to Boulter, who overpowered the higher-ranked Putintseva in their opening set to claim it 6-3 with some fearless forehand winners.
But she landed awkwardly in the third game of the second set en route to losing it 6-2 to the world number 38 as Putintseva ensured the second singles rubber would also go to a deciding set.
The Kazakh then showed her fighting spirit to save three match points before beating Boulter 8-6 in a tense tie break to level up the clash with the reverse singles and a doubles match still to play.
Reflecting on Boulter’s defeat, Great Britain captain and London 2012 Olympian Anne Keothavong said: “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. It could be a combination of a number of factors, pressure affects people in different ways.
“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.”