Baltimore's Beth Yingling and Forster Campbell bowled 20 box match games of 275 and 236, respectively, to clinch championships in the third annual Baltimore-Washington Youth Duckpin Invitational yesterday in Laurel.

Yingling, 15, topped D.C. champion Melanie Gonslaves, 275-213, after crushing Sharon Grubowski, 295-214 in the Baltimore girls final. The Northern High sophomore said she "did't have any special strategy.

"I was kind of nervous," Yingling said, "But I just decided to get out there and bowl."

In the boys competition, Campbell, 19, defeated Bill myers of Randallstown, 276-252, to capture the Baltimore championship and later, in the intercity championship, Campbell posted a 236-224 match game victory over Kerrick Keenan of Bailey's Crossroads.

Campbell, who climbed from fourth place, admitted she was tense during the final match but said the earlier elimination games were good preparation.

"I felt it was an advantage to work my way up -- to see how I worked under pressure," Campbell said. Campbell, who just completed his first year at Coppin State, will be too old for competition next year.

Yesterday was the final round of duckpin competition which began Tuesday in Prince George's County. The tournament, which opened with 160 participants from the Baltimore-Washington area, advanced the top four pinfall competitors (girls and boys) from each city meeting to the final round.