British number one Johanna Konta and number two Heather Watson were both knocked out in the second round of the Aegon Classic in Birmingham.
World number 19 Konta, 25, lost 6-3 6-3 to Belgium's Yanina Wickmayer, who is 30 places below her in the rankings.
Watson, 24, ranked 55th, lost 7-5 6-4 against Czech Barbora Strycova, who has been as high as number 12 in the world but is currently 30th.
Fellow Britons Naomi Broady and Tara Moore were beaten in the first round.
"I've played four very good matches, so I'm really happy with the amount of time I've been able to get on the grass," said Konta.
"However, I need to get used to players coming out and playing at a better level against me and that's inevitable as I climb the rankings."
Watson felt that Strycova handled the distractions of playing on a small court better than she did.
"On the court we were on, I was getting distracted and I don't think my focus was there today," she said.
"I feel like I'm striking the ball really well, there are just a few tweaks that I need to make going into Wimbledon. I'm feeling very optimistic, even though I lost."
The next grass event starts at Eastbourne on Sunday, before Wimbledon begins on 27 June.