Irvington, the top seed and three-time defending Section 1 and state Class B champion, will face No. 2 Blind Brook in Saturday's 7 p.m. championship game at the County Center.
Martins scored 11 of her 25 points and Lai added nine of her game total 17 in the first quarter. The pair hit 11 of 12 free throws in the opening period as the Bulldogs took a 22-13 lead.
Alyssa Chipelo, Kristin Foresti and Emily Bohl did the bulk of the scoring as Dobbs Ferry battled through the first half and stayed with the defending champions to trail 45-25 at halftime.
The Bulldogs took advantage of their chances at the free throw line, making 27 of 31 in the game.
Irvington coach Gina Maher is looking to win her 11th Section 1 title. The Bulldogs won seven straight championships under Maher from 1983 to 1988 and the last three in a row.
Lauren Chafizedeh and Laurilyn Gelardi each scored 13 for Irvington. Martins grabbed 22 rebounds and Lai handed out nine assists.
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