Laura Robson was among the winners but there were differing fortunes for Britain's young hopefuls on the opening day of play at the AEGON Classic in Birmingham.
Robson and Heather Watson, who have both secured grand slams at junior level, were looking to win their first main-draw matches on the WTA Tour.
Robson, who came through qualifying, faced Switzerland's Stefanie Voegele and she achieved a third victory of the week, although not in the way she would have wanted.
The 16-year-old battled hard to take the first set 6-4 but had just been broken to trail 1-0 in the second when her opponent, who is ranked 78th in the world, retired with a back injury.
The reward for Robson is a second-round match against third seed and rising star Yanina Wickmayer.
Russia's Alla Kudryavtseva was the opponent for 18-year-old wild card Watson who could not emulate her fellow British teenager, going down 6-4 6-3.
Another British casualty was Mel South who twice let substantial leads slip away against former top-10 player Anna Chakvetadze.
South led by a set and 4-1, and then 4-1 in the decider, but lost five games in a row on both occasions to succumb 3-6 6-4 6-4 to Chakvetadze, who is now ranked outside the top 100.
Eleventh seed Melinda Czink was beaten 7-5 6-4 by New Zealander Marina Erakovic but fellow seeds Magdalena Rybarikova, Angelique Kerber and Tamarine Tanasugarn all progressed to round two.
Other notable winners included Indian superstar Sania Mirza, playing her first match since marrying Pakistan cricketer Shoaib Malik in April, and Mirjana Lucic.
Croatian Lucic looked set for a glittering career when she burst onto the scene in 1997, winning a WTA Tour title at the age of 15 before reaching the semi-finals at Wimbledon two years later.
But personal and financial problems took their toll and she slid off the radar, barely playing at all between 2003 and 2007. Since then the 28-year-old has been playing largely on the ITF circuit in the USA, improving her ranking to 195th, and today's 6-1 6-2 win over Mariana Duque Marino was her first in the main draw of a WTA Tour event for more than three years.
Britons Katie O'Brien and Naomi Broady both went out in the first round.
O'Brien, the British number three, was beaten 6-3 6-4 by Kazakhstan's Sesil Karatantcheva while Broady, ranked eighth nationally, went down 6-4 6-4 to American Shenay Perry, who is 150 places above the Briton in the world rankings.