Marin Cilic retained his Zagreb Indoors crown on Sunday by beating top seed Tommy Haas 6-3 6-4 in the final.
The world number 37 hit 10 aces and won 80% of points behind his first serve en route to securing victory in one hour and 19 minutes.
Cilic has now won the ATP 250 tournament four times in the last six years.
He has lost just one of his last 21 matches at the event.