Ferrer past Soderling into Valencia final
Granollers, playing in the main draw as a lucky loser from the qualifying rounds, held his nerve to beat former world number six Gilles Simon of France 6-4 6-4.
It will be the 24-year-old Barcelona native's second final on the ATP Tour after his only career title in Houston in 2008.
The first semi in the indoor arena pitted zippy world number eight Ferrer against imposing Swede Soderling, ranked five, and Ferrer's athleticism and tenacity eventually prevailed.
Valencia resident and fourth seed Ferrer started strongly and broke for a 5-3 lead before serving out the set with aplomb.
Soderling, a finalist at this year's French Open, immediately hit back, moving 3-0 ahead in the second set and going on to level the match with a combination of powerful, accurate serving and booming groundstrokes.
Ferrer grabbed the crucial break of the decider in the sixth game and sealed victory on his first match point when Soderling hit a forehand over the baseline.
"I would highlight the first set above all because he played really well but I managed to get the break point," Ferrer, the 2008 winner before the event moved from clay to hard court, said afterwards.
"He injected a lot of power in the second set but thanks to a good serving performance I could dominate the third and win the match," he added. "Winning the final would be one of the greatest joys of my career."
The 28-year-old has a good chance of clinching one of the three remaining berths at the November 21-28 Tour finals in London, for which Rafael Nadal, Roger Federer, Novak Djokovic, Andy Murray and Soderling have all qualified.
Simon, ranked 52, won his seventh Tour title in Metz in September and looked to be getting back to something like his best form.
However, he hit six double faults and lost his serve four times against Granollers, who was only included in the main draw after Simon's injured compatriot Jo-Wilfried Tsonga withdrew.