Defending champion Katie Boulter edged out Harriet Dart in a marathon all-British tie to reach the second round of the Nottingham Open.
Opening her grass-court season, third seed Boulter won 6-7 (5-7) 6-4 7-5 in a contest lasting three hours and 13 minutes.
British number one Boulter's victory in Nottingham 12 months ago marked her first WTA title.
The 27-year-old will play Viktorija Golubic of Switzerland or Canada's Rebecca Marino next.
"That was an absolute battle," said Boulter, ranked 30th in the world.
"[Dart] is an incredible grass-court player. I tried to do the best I could because she was playing seriously good stuff.