Wendy Kay Chung and Wei-Jing Zhu tied for first place last night in the annual Westinghouse-sponsored Science Talent Search for high school seniors. For the first time in the competition's 45-year history, the top five winners were all born in Asia or of Asian parentage.

Both Chung, 17, and Zhu, 16, will receive $20,000 college scholarships -- the second time two students have tied for the competition's first place.

Chung, whose project studied the behavior of the Caribbean fruit fly, is first in her senior class of 847 at Miami Killian High School in Florida.

Zhu, who selected a problem in algebraic number theory for his project, was born in Canton, China, and now lives in Brooklyn, N.Y. He is the first-ranked senior in a class of 1,159 at Brooklyn Technical High School.

Third place (a $15,000 scholarship) was awarded to Yoriko Saito, 18, of Homewood, Ala.; fourth and fifth places (each including a $10,000 scholarship) went to George Jer-Chi Juang, 17, of Queens, N.Y., and Anh Tuan Nguyen-Huynh, 17, of Chagrin Falls, Ohio, respectively.

The announcements were made last night at a black-tie banquet at the Mayflower Hotel that was the culmination of a five-day gathering for the 40 finalists, who come from 14 states and were competing for $140,000 in scholarships and cash awards.