MEMPHIS, TN, USA - It was a Sunday start for 12 players in this week's Cellular South Cup, and there was certainly no rest for two seeds who exited the $220,000 tournament after hard-fought tussles.

Alla Kudryavtseva was the highest to fall, the fourth-seeded Russian succumbing to Czech Sandra Zahlavova - who gave Venus Williams such a fright at the Australian Open - in straight sets, 76(6) 64.

Eighth seed Vania King of the US was also left to rue her chances after falling in three see-saw sets to Magdalena Rybarikova, 61 36 76(9). The reigning Wimbledon and US Open doubles champion held match points against the Slovak, but will now focus on defending the doubles title she won here last year with Michaella Krajicek, who is again her partner this week.

Although up-and-coming Christina McHale was outclassed by seventh-seeded Renata Voracova in straight sets, 62 61, there was better news for the American contingent with Coco Vandeweghe's 63 62 defeat of qualifier Anna-Lena Groenefeld. Vanedweghe served seven aces and never faced a break point, whereas Groenefeld hit her first service mark just 47% of the time.

Alexa Glatch also advanced with ease, 62 60 - albeit at the expense of fellow American Beatrice Capra, a wildcard. The only other match of the day saw British qualifier Heather Watson reel in a second set surge by the Czech Republic's Andrea Hlavackova, 63 75.

Tournament No.3 seed Melanie Oudin makes her first appearance on Monday night, against Anastasia Pivovarova of Russia.