'S-HERTOGENBOSCH, The Netherlands (AFP) - Thai veteran Tamarine Tanasugarn, who had to come through qualifying, defeated Ukrainian eighth seed Alona Bondarenko 6-2, 6-4 on Friday to reach the final of the 175,000-dollar WTA grasscourt event.

Tanasugarn, who beat the other Bondarenko sister, Kateryna, in the first round, had no problem beating the second sister in the semi-final.

"They're both very good players," said Tanasugarn.

"It's not easy to have two sisters in the Top 50. They are both tough opponents and both played very well."

Tanasugarn has battled her way through the tournament, beating Ashley Harklewood and local favourite Michaella Krajicek, who was looking at one point to be a likely contender for the final after defeating fifthseed Flavia Pennetta in the first round.

For Tanasugarn the tournament got underway with a tiring start.

"I arrived from Birmingham on Saturday morning and had to play two qualifying matches on the same day. I was very exhausted after that, but I have been able to hit more balls and play some matches on the surface and get used to it."

On Saturday, she faces French Open runner-up Dinara Safina in the final.

The third seeded Russian defeated world No.5 and top-seeded compatriot Elena Dementieva 6-3, 6-2 in her smei-final.

Despite her good form - this is the Russian's third straight final - Safina still worries about playing on grass courts.

"I haven't had a lot of time to adjust to the grass. This week I've been able to get some practice in and these matches have helped. I think I'm really getting adjusted and this tournament will help me get ready for Wimbledon."

In the ATP event, top seed David Ferrer of Spain reached his first grasscourt final with a 7-6 (7/4), 6-1 victory over Argentine teenager Juan Martin del Potro.

Ferrer will look to win his seventh career ATP title when he takes on Frenchman Marc Gicquel in the final. World number 60 Gicquel fought back from a one set deficit against seventh-seeded Argentine Guillermo Canas to prevail 3-6, 6-0, 6-4.