Wimbledon, England -- (Sports Network) - Defending champion Venus Williams and Russian Elena Dementieva both advanced in third-round action at Wimbledon on Saturday.

Williams, the seventh seed, joined her sister in the fourth round as she easily advanced past Spain's Maria Jose Martinez Sanchez, 6-1, 7-5 in just one hour, 12 minutes.

The 28-year old Williams is looking for her fifth title here.

Dementieva, the fifth seed, had trouble in her first set against Argentina's Gisela Dulko, but eventually took the set and won the next in a 7-6 (7-2), 7-5 match that took two hours, six minutes to finish.

Other third-round winners on Saturday included Thailand's Tamarine Tanasugarn and Russia's Alisa Kleybanova. Tanasugarn bounced back from a loss in the first set and rallied for a 4-6, 6-4, 6-4 win over New Zealand's Marina Erakovic while Kleybanova had an easy time with Japan's Ai Sugiyama, 6-4, 6-4.