Paire is one of three French semi-finalists at the tournament on home soil, with Michael Llodra and Richard Gasquet also progressing. Finland's Jarkko Nieminen is the sole foreign player remaining ahead of the weekend's conclusion.
Elsewhere, Austrian fourth seed Jurgen Melzer made the semi-finals of ATP Zagreb with a straight sets win over Lukas Rosol.
World number 29 Melzer stormed past his Czech opponent to earn a last-four match against Robin Haase after the Dutchman beat Philipp Petzschner.
Top seed and local favourite Marin Cilic eased past Blaz Kavcic in straight sets in the final last-eight encounter, but compatriot Ivan Dodig lost handily to third seed Mikhail Youzhny.
ATP Zagreb quarter-final results:
Robin Haase (Netherlands) beat Philipp Petzschner (Germany) 6-4 3-6 6-0
4-Jurgen Melzer (Austria) beat Lukas Rosol (Czech Republic) 6-4 6-4
3-Mikhail Youzhny (Russia) beat Ivan Dodig (Croatia) 6-3 6-2
1-Marin Cilic (Croatia) beat Blaz Kavcic (Slovenia) 6-3 7-6(5)
ATP Montpellier quarter-final results:
Michael Llodra (France) beat Jan Hajek (Czech Republic) 7-6(3) 6-1
Jarkko Nieminen (Finland) beat Sergiy Stakhovsky (Ukraine) 4-6 6-3 7-6(2)
8-Benoit Paire (France) beat 4-Gilles Simon (France) 7-5 7-6(4)
3-Richard Gasquet (France) beat 6-Julien Benneteau (France) 6-1 4-6 6-1