He will face Guillermo Garcia-Lopez of Spain, who beat Joao Sousa of Portugal 6-1, 6-1 in the second semifinal.
The 36th-ranked Gulbis broke Przysiezny in the third game of the second set and again in the ninth game to seal the victory on his second match point.
The Latvian reached his second final of the season after winning his third career title in Delray Beach in February.
The 74th-ranked Garcia-Lopez won six consecutive games in the first set and broke his opponent twice in the second before sealing the win on his second match point. The Spaniard, who was runner-up in Bucharest and Rome in April, is looking for his third career title. He last won in 2010 in Bangkok.
Przysiezny and Sousa were playing in their first career ATP tour semifinals.