Spain's Ferrer, seeded sixth, schooled Benneteau as the Frenchman played in his first semi-final at the elite Masters 1000 level.
He needed just 71 minutes to seal the victory and give himself a shot at adding a second title of 2014 to the trophy he lifted in Buenos Aires.
The 32-year-old Spaniard also reached the final at Hamburg this year, but he last played a Masters final in November, when he lost to Novak Djokovic at Paris Bercy.
Ferrer will aim for his 22nd career trophy when he faces off on Sunday against either second-seeded Roger Federer or Canadian Milos Raonic, the fifth seed.
Ferrer, noted for his foot speed and dogged retrieving, got comfortable with a break in the opening set to take the opener in 39 minutes.
"I played very consistently, and got the break, then I could play with calm," he said, calling the match "maybe my best of the week".
"I played without a lot of mistakes but it was difficult to return sometimes."
Ferrer took a 4-1 lead in the second set and while Benneteau put up a last-gasp fight he was able to wait for the exhausted Frenchman to finally make an error on the fifth match point.
"I'm going step by step," Ferrer said. "Tennis is always a surprise. When I looked in my quarter of the draw and saw Novak Djokovic and Jo-Wilfried Tsonga there, I knew it was not easy.
"But as they lost, I took my chance and got into the final. I'm trying to improve my game every day. Watching the top 10 guys is a great inspiration to improve also.
"I'm feeling very comfortable on hardcourts. On those I can play more with my timing than with power."
Federer has a 5-0 record over big-serving Raonic, including a straight-sets semi-final triumph at Wimbledon this year.
But the 17-time Grand Slam champion from Switzerland said he couldn't afford to be complacent.
"I will focus on my own game, very simple and straightforward," he said. "Because of his serve, you just never feel you're quite a peace, and especially in the best-of-three match.
"If I'm playing well and my reaction is there, I feel good about my chances. I'm aware of how good Milos is on this kind of court."
In women's action at the combined ATP and WTA event, top-seeded Serena Williams booked a finals berth with a 2-6, 6-2, 6-4 win over Caroline Wozniacki.
She'll face the winner of the battle between former world number ones Maria Sharapova and Ana Ivanovic.