Gulbis lost to Greece's Stefano Tsitsipas 6-4, 6-4 on Sunday, with the win making Tsitsipas the first Greek to win an ATP tour event.
Gulbis was unable to find consistency with his big serve, with just 50% of his first serves finding their mark, and as a result Tsitspiras ran out a deserved winner.
"Congratulations on your first title. I know it's a big deal to win your first ATP title, so enjoy it. I wish that it's not the last one," Gulbis told his opponent on court after the match.
However the former world number 10 sees his ranking rise from 145 to 104 as a result, as well as a cash prize of more than 50,000 euros. His next outing is the Basel tennis tournament in Switzerland this week.
Meanwhile in Moscow, Latvia's top-ranked female tennis player Anastasija Sevastova fell at the semi-final stage. She lost to Tunisian qualifier Ons Jabeur in three sets at the WTA Kremlin Cup event. Nevertheless her strong showing continues a great season for the player who has risen past Aļona Ostapenko in the rankings.