Britain's number two Johanna Konta beat Monica Puig 4-6 6-4 7-6 (7-5) in their delayed match to reach the Nottingham Open quarter-finals.
The world number 147 took the deciding tie-break to defeat her opponent - who is ranked 58 places above her - after two hours and 19 minutes of play.
Konta, 24, and the Puerto Rican broke each other twice in the final set after bad light on Wednesday halted play.
The Briton faces Monica Niculescu, of Romania, in the last eight on Friday.
"It's always difficult not to finish a match on the same day.