Toyomura scored seven points and teammate Marina Kofukugawa scored nine of her 11 points in the first half as Keio raced to a 25-9 lead.
Third-seeded Keio, which is in Purchase, will meet the winner of the semifinal between top-seeded Haldane (Cold Springs) and No. 4 Alexander Hamilton of Elmsford in the championship game Friday at 7 p.m. in the County Center.
No. 2 Tuckahoe, down 25-9 at halftime, mounted a second-half comeback and narrowed Keio's lead to 35-25 in the third quarter. Brionna Johnson led Tuckahoe with 12 points and 10 rebounds and teammate Jahnea Bell added six points.
Marina Kukobo added 10 points for Keio, which raised its record to 13-7 overall.
Tuckahoe finished the season with a record of 13-6.
Section 1 Championship Week Semifinal Schedule
Wednesday, Feb. 26 Class A girls semifinals: No. 2 Albertus Magnus vs. No. 3 Rye, 3 p.m. Class A boys semifinals: No. 2 Walter Panas vs. No. 6 Tappan Zee, 4:45 p.m. Class A girls semifinals: No. 1 Beacon vs. No. 4 Peekskill, 6:30 p.m. Class A boys semifinals: No. 1 Eastchester vs. No. 4 Harrison, 8:15 p.m.
Thursday, Feb. 27 Class AA girls semifinals: No. 3 Clarkstown South vs. No. 7 Mahopac, 3 p.m. Class AA girls semifinals: No. 1 Ossining vs. No. 4 Horace Greeley, 4:45 p.m. Class AA boys semifinals: No. 2 Clarkstown South vs. No. 6 Spring Valley, 6:30 p.m. Class AA boys semifinals: No. 1 Mount Vernon vs. No. 5 Mahopac, 8:15 p.m.
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