Martina Navratilova withstood a lengthy tie breaker and a warning from the umpire before she beat Bettina Bunge, 7-6 (13-11), 6-3, to reach the semifinals of the $150,000 Eastbourne (England) Grasscourt Tennis Championships yesterday.

At a crucial stage in the tie breaker, Navratilova slammed a ball into the crowd in frustration following a line call that gave her opponent set point at 9-8. The ball almost hit a spectator and the umpire warned Navratilova for "ball abuse."

Navratilova evened the tie breaker with her next serve and survived two more set points against her before clinching the set on her fifth set point.

At the changeover following the ball-slamming incident, Navratilova apologized to the spectator she nearly hit. Later, she said she was angry because, when she queried the line call, the umpire told her to play on immediately instead of allowing her a 30-second break between points.

"That's what upset me and I tried to hit the net with the ball," she said. "As a result I almost hit someone at the back of the court. I would have been really upset if I had. I kept my cool and won the next point on my serve and after that I calmed down."

In the semifinal, Navratilova will meet No. 3 Manuela Maleeva, who routed No. 12 Kathy Rinaldi, 6-1, 6-0. In other quarterfinal matches, unseeded Pascale Paradis squandered a set and 4-2 lead and lost, 6-3, 4-6, 5-7, to Wendy Turnbull, and Helena Sukova defeated Barbara Potter, 6-0, 7-6 (7-5).