Fifth-seeded Verdasco will play his second final in two weeks after overcoming early frustrations to top Ferrer 6-7 (3), 7-5, 6-1, denying his Davis Cup teammate a third straight appearance in the final.
"I had confidence after coming back into the game in the second set," said Verdasco, who lost last week's Monte Carlo Masters to Rafael Nadal. "I'll have to recover quickly to be in good shape for tomorrow."
Verdasco will try to make it nine straight Spanish winners at Godo when he plays Soderling, who reached Sunday's final after winning 6-1, 6-4 over Thiemo de Bakker of the Netherlands.
While Verdasco was worn out by the 2-hour, 37-minute match played in the hot sun, Soderling needed only 76 minutes to get past the unseeded De Bakker and become the first Swedish player to reach the final since Magnus Larsson in 1995. No Swede has won in Barcelona since Kent Carlsson did 22 years ago.
Ferrer rallied from early jitters to save three break points in the opening game but succumbed to Verdasco in his second service game to trail 2-1. Ferrer immediately rallied for a break of his own to make it 2-2 and neither player dropped serve until the tiebreaker, when Ferrer pulled away.
Ferrer controlled the tempo from the baseline and slapped a crosscourt forehand winner into the corner for another break and a 3-2 lead in the second set.
"In the first set I felt a little heavy in the legs, I was moving poorly and I was late getting to a lot of balls," Verdasco said. "I got better with the game, it was a little strange."
Verdasco sparked back to snap his opponent's momentum with two breaks in the second set, including to even it at 4-4 when Ferrer hit long. The momentum shifted to the ninth-ranked Verdasco, who clinched the set on his fifth try as Ferrer netted.
"I had the occasion and took advantage," said Verdasco, who will be going for his second title of the season. "Getting the two breaks in the second set, that was tough."
Verdasco stroked a forehand down the near line for his fifth break of the match before holding serve for a 5-0 lead in the deciding frame, which he clinched when Ferrer hit out.
Soderling broke De Bakker's opening service game to get himself going. The eighth-ranked Soderling then saved two break points in the third game to get out to 3-0 on his way to a first-set lead in a match heavy on groundstrokes.
Soderling was up 4-0 in the second before his concentration started to slip as De Bakker broke back to cut the lead to 5-4. Soderling, who didn't drop a set all week, saved a break point before taking it when the Dutchman netted.