Johanna Konta won the all-British battle against Heather Watson to reach the quarter-finals of the Nature Valley Open in Nottingham.
It was a second meeting on the WTA Tour for Britain's top two female players and, like the previous one in Indian Wells last year, Konta came out on top.
The windy conditions made life difficult for both players but ultimately it was the extra power of Konta, who reached the final here 12 months ago, that made the difference in a 6-4 7-6 (7/5) victory.
Konta has a huge amount of points to defend during the grass-court campaign and her confidence remains fragile but, aside from a host of errors at the net, this was a good performance from the 27-year-old.
Watson struggled to deal with the Konta return in particular, and a single break in the fifth game was enough to decide the opening set. Watson made the better start to the second and led 4-1 but Konta fought back and edged a close tie-break.
Konta said on Eurosport: "One hundred per cent it was not easy and conditions made it that much harder. It's never easy to play a compatriot. I just tried to keep my focus on my side of the court. I feel fortunate to come through, there was very little in it."
The fourth seed, who will face Slovenia's Dalila Jakupovic next, was the second British player to make it through to the last eight after an excellent win for wild card Katie Boulter (below) over former US Open champion Sam Stosur.
The 21-year-old will play in a WTA Tour quarter-final for the first time following a 7-6 (8/6) 6-1 triumph and is set to break into the world's top 50.
Boulter said: "It's really exciting. It's a huge step for me. She's a grand slam winner, and it's the first one of those that I've beaten. It was a really quick second set but I dug in really deep in the first. I thought I held my nerve really well and found a way to win."