Johanna Konta believes she is 90 per cent of the way to rediscovering her best form after a first-round defeat by Petra Kvitova at the Nature Valley Classic.
Konta paid the price for her drop in ranking by drawing the defending champion and lost a close contest 6-3 6-4 to bring an end to British interest in the singles after Heather Watson was beaten 7-6 (7/2) 7-5 by Ukraine's Lesia Tsurenko.
"I think for 90 per cent of the match I was shoulder to shoulder with her, which was a very positive thing for me," said Konta.
"That 10 per cent is what I'm working on right now to be able to do just that bit better and to come through in some of those close moments."
After losing the first set, Konta was the better player for much of the second but could not take either of two break-point chances at 4-3 and then served two consecutive double faults to drop serve in the following game, with Kvitova serving it out.
Konta has now lost her last six matches against top-10 players, dating back to her quarter-final victory over Simona Halep at Wimbledon.
She said: "I won't be kicking myself. I did a lot of good things, which is more what I want to be taking from the match. Ideally I don't want to be double-faulting twice in a row, however she also puts a lot of pressure on you when she's returning and she has a very big presence, so I think that's also credit to her and how she was returning."
Wimbledon champion and top seed Garbine Muguruza had no trouble easing into the second round with a 6-1 6-2 victory over Anastasia Pavlyuchenkova, while second seed Elina Svitolina was a 6-1 3-6 6-1 winner against Donna Vekic.