Darcis won a rain-interrupted semifinal Saturday against top-seeded Frenchman Marc Gicquel 7-6 (7-3), 3-6, 7-5. Montanes beat fellow Spaniard Oscar Hernandez 6-1, 6-3.
Darcis, seeded third, won his first-ever ATP singles title last year at this event. He earned his second earlier this year with a victory over Robin Soderling in Memphis.
The last player to successfully defend the Dutch Open crown was Balazs Taroczy, who won five straight from 1978-82.