Zarina Diyas and Heather Watson were the seeded casualties on the first day of main-draw action at the Family Circle Cup in Charleston . Diyas , the 11th seed from Kazakhstan , won the first set against Czech qualifier Lucie Hradecka but was beaten 4-6 6-1 6-3 . British number one Watson , seeded 16th , gave up 14 break points and lost her serve seven times en route to a 6-3 4-6 7-5 defeat to Croatian teen Donna Vekic in a hard-fought match lasting more than two and a half hours . Heather Watson crashed out in Charleston after a narrow victory to Donna Vekic . The other seeds in action , Irina-Camelia Begu and Mona Barthel , progressed in straight sets . Begu , seeded 13th , required two hours and a second-set tie-break to win 6-2 7-6 ( 7/5 ) against German qualifier Laura Siegemund , who had hammered Japanese veteran Kimiko Date-Krumm 6-0 6-1 to reach the tournament proper . Barthel , two places lower than Begu in the seedings , broke serve four times in a 6-3 6-3 win over Hungary 's Timea Babos . Chanelle Scheepers of South Africa won 6-2 2-6 6-4 against New Zealand 's Marina Erakovic while Croatian Ajla Tomljanovic beat Romania 's Alexandra Dulgheru 7-6 ( 7/5 ) 4-6 6-4 . There was an easier time for Diyas ' Kazakh compatriot Yaroslava Shvedova , who beat Switzerland 's Stefanie Voegele 7-5 6-2 . The two all-American ties ended with Lauren Davis beating Grace Min and wild-card Sachia Vickery victorious against qualifier Jessica Pegula , both in three sets . Shelby Rogers brushed aside Spain 's Silvia Soler-Espinosa 6-3 6-1 but Irina Falconi was dismissed just as comfortably by Tatjana Maria of Germany and Nicole Gibbs and Christina McHale lost in straight sets to Shuai Zhang and Danka Kovinic respectively . Kristina Kucova beat Mirjana Lucic-Baroni while Evgeniya Rodina saw off Yulia Putintseva . The last match of the evening went the distance with Ukrainian qualifier Kateryna Bondarenko eventually beating Alison Riske of America 6-4 4-6 6-1 after two hours on court .
The British No 1 was edged out in a keenly fought contest which lasted two-and-a-half hours . Vekic won 6-3 , 4-6 , 7-5 to eliminate the 16th seed . She will play either Madison Brengle or Edina Gallovits-Hall .