Champion and top seed Maria Sharapova was given a torrid time before she edged out Samantha Stosur 6-3, 3-6, 6-1 to reach the quarter-finals of the pre-Wimbledon Edgbaston grasscourt tournament on Thursday.
In a repeat of last year's third-round match, the Russian was given her first real test on the surface by the 16th-seeded Australian.
The Wimbledon champion used her greater expertise on the slick surface to romp through the third set having dropped the second.
"She's a much better player than when I played her last time," said Sharapova, who extended her head-to-head record to 4-0 against Stosur.
"She served and volleyed today which she didn't do the last time I played her.
"She really pushed me in the third set but I think it's really good to push me... I enjoy the challenge of being pushed (because that's) when I have to figure out a way to win."
Almost 12 months on from her triumph at the All England Club, Sharapova is looking forward to returning to the tournament which turned her into a global phenomenon.
"I won it (Wimbledon) last year and no one can take that away from me," said the 18-year-old.
"A whole year has gone by but it seems like only yesterday.
"Every tournament I play there are expectations, you're expected to do well if you want to be the champion. It's part of the sport."
In other action, sixth seed Shinobu Asagoe failed to reach the last eight after she was ousted 6-4, 6-4 by Russia's Anna Chakvetadze.
