"She has a lot of experience and really knows how to play, so I had to take care of things on my side of the net."
Sharapova, 27, raced into a 3-0 lead winning eight of the first 10 points and took the first set in just 27 minutes with some powerful ground strokes.
The Russian picked up where she left off in Friday's 6-4 6-3 quarter-final win over world number three Agnieszka Radwanska and converted six of her eight break points against Errani.
The 26-year-old Italian was never allowed to find her rhythm as Sharapova dominated the second set.
The Russian, who has never won a tournament three times running, will face fellow former number one Ana Ivanovic in Sunday's final after her 6-3 7-5 victory over Jelena Jankovic in an all-Serbian semi-final.
Sharapova leads the series 7-2, with Ivanovic, ranked 12th in the world, having lost twice last year on clay to the Russian - in the Stuttgart quarter-finals and Madrid semi-finals.
"It is going to be tough. Maria has been playing great and hasn't lost a match here," Ivanovic said.