Britain's Johanna Konta beat Greece's Maria Sakkari 6-4 7-6 (7-3) to reach the third round of the Nature Valley International at Eastbourne.
The world number 19 was 5-3 down in the second set but fought back to secure victory in one hour 37 minutes.
Konta, 28, will play Ons Jabeur in the third round after the Tunisian defeated Mandy Minella 2-6 6-2 6-1.
"There was so little in this match. I felt she was playing better than me for most of that match," Konta said.
"I'm really pleased to have stayed tough and created as many opportunities as possible."
Wimbledon champion Angelique Kerber progressed by beating Sam Stosur 6-4 6-4 and plays Rebecca Peterson in the last 16 after the Swede saw off Lesia Tsurenko 7-6 (8-6) 6-4.
Defending champion Caroline Wozniacki beat German Andrea Petkovic 6-4 6-4 but the Dane faces a tougher challenge in the third round, where she will play eighth seed Aryna Sabalenka.
Second-set wobble for Konta
Konta had to save two break points in the fourth game of the match before a drop shot-volley combination saw her break Sakkari for a 3-2 lead.
Having taken the first set, the French Open semi-finalist appeared the more likely player to break through in the second set until a fall seemed to unsettle her and Sakkari broke to love for a 5-3 lead.
However, she was unable to serve out the set and Konta wrapped up the win in a tie-break with a forehand winner.
Earlier, France's Alize Cornet knocked out Ukrainian fifth seed Elina Svitolina 7-5 6-2 in a match delayed by rain on Monday. She will play Zhang Shuai in the third round after the Chinese player saw off Daria Gavrilova 6-3 6-1.
Sixth seed Simona Halep enjoyed a straightforward 6-2 6-0 win against Taiwan's Hsieh Su-wei and plays Polona Hercog in the third round, but former US Open champion Sloane Stephens squandered a one-set lead against 2018 Wimbledon semi-finalist Jelena Ostapenko to lose 1-6 6-0 6-3.
Ostapenko will face world number 52 Ekaterina Alexandrova, who beat Belinda Bencic 6-7 (6-8) 6-2 6-3.
The Swiss 10th seed was playing her second match of the day after rain pushed her first-round game back.
Dutch third seed Kiki Bertens defeated Yulia Putintseva 6-4 6-1 and next plays Germany's Anna-Lena Friedsam, who upset 16th seed Anett Kontaveit 6-3 6-4.