Eastbourne - Qualifier Monica Puig extended her fairytale run at the WTA Eastbourne event, defeating Kristina Mladenovic 7-6 (8/6), 4-6, 6-3 on Thursday to move into the quarter-finals.
Shortly after the 43rd-ranked Puerto Rican booked her place, top seed and 2008 champion Agnieszka Radwanska was caught out by more rain moving onto the south coast.
Radwanska was leading 12th seed Dominika Cibulkova 6-4, 2-0 when their quarter-final was forced off court at Devonshire Park.
The world number three Pole was looking to pad a 7-4 career record over former Australian Open finalist Cibulkova from Slovakia.
Puig, who spent nearly three hours in defeating French Open doubles champion Mladenovic, said that mental strength is an important part of her regime.
"The sports psychology part, my team takes care of. My coach and everybody on my team tries to get me mentally prepared for every single type of situation that I'm going to encounter on the court.
"The strength comes from within, but I think it just gets stronger due to the experience I have had in the past. I've had had several matches where I have been the softer one and I have caved to the pressure.
"But now I have some of these matches under my belt (from difficult situations) and I have been able to pull it out."
Puig also made it to the Sydney final in January from a qualifying start, facing two-time grand slam winner Svetlana Kuznetsova in the title match.
Puig survived nine double-faults and ten aces from her opponent, breaking six times but forced to save 18 of the 23 break points she faced in the see-saw battle on the grass.
"We're both putting so much pressure on each other's serves. It was basically about me staying focused and doing what I had to do, which is be as aggressive as I could and just keep my head together.
"There were more double faults - felt like a million to me - but the most important thing is I was able to put those behind me and just keep focusing on what I had to do next, which is very important.
"I always try to stay as positive as possible, but it definitely does feel good to get this win under my belt and move into the semis."
With weather threatening to disrupt the programme, two remaining quarter-finals looked in danger of starting.
Russia's Elena Vesnina, the 2013 champion, was playing Czech 10th seed Karolina Pliskova, while British 11th seed and Eastbourne local Johanna Konta was playing Russian Ekaterina Makarova, winner of the event in 2010.