The Spaniard broke the Russian twice in the first set, and took a quick 4-0 lead in the second, building up a momentum that Davydenko failed to reverse.
The Russian made many unforced errors and ended the match with a backhand blunder, while Robredo’s game was consistent.
“I did what I had to do to win. I didn’t have to take risks with hitting winners because Davydenko missed so many shots,” Robredo said.
Meanwhile, home favourite Jonas Björkman notched up his 48th doubles title, winning the tournament with partner Thomas Johansson.
The win means that Björkman now holds a record six Båstad titles.