Gaston Goes a Long Way to Defeat Chen Olsen, 1 Up : Women’s golf: She wins match of Porter Valley friends on 18th hole, reaches semifinals of State Amateur.

Andrea Gaston of Chatsworth moved a step closer to defending her state golf title by winning a quarterfinal match Friday in the Women’s California Amateur at the Golf Club at Quail Lodge in Carmel, Calif.

It wasn’t exactly easy.

In a match that went down to the final hole, Gaston defeated one of her pals, Linda Chen Olsen of Granada Hills, 1 up.

“It was anybody’s match,” Gaston said. “Both of us played well. If I’d have lost, I’d have been gratified because we both played so well.”

Olsen, who like Gaston is a member of Porter Valley Country Club in Northridge, was co-medalist in Tuesday’s qualifying round.

Gaston, 36, will face Eva Monisteri of San Mateo today at 7:30 a.m. Monisteri defeated Stephanie Gerrish of Aptos, 1 up. Monisteri and Gaston played at San Jose State.

Olsen was 2 up after eight holes, but Gaston won three of the next four holes. Gaston took the lead for good with a birdie on No. 14.

The pair halved the final four holes. Olsen missed a 30-footer for birdie at No. 18 that would have sent the match to a playoff.

Diane Irvin of Pacific Palisades and Juli Christopher of Saratoga will play in the other semifinal.