The top-seeded Raonic posted a 6-4, 6-3 victory over Haas, becoming the first player in the Open Era to capture the Bay Area event in three straight years.
Prior to 1968, Tony Trabert notched wins at the tournament from 1953-55.
The 22-year-old Raonic, who has never lost a set in San Jose, fired 19 aces.
The fourth-seeded Haas was trying for his 14th career title.
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