French Open Champion, Wawrinka served strongly to beat Gilles Muller of Luxembourg 6-4 7-6 to reach his fourth final of the year.
Paire upset home favourite, Kei Nishikori, 1-6 6-4 6-2, to reach his first ATP Tour 500 final.
Nishikori came into the tournament as defending champion and looked set for successive titles, as he coasted through the first set.
Paire needed a medical timeout to reinforce strapping on his ankle, and the patch-up helped as he found a second win against an increasingly-nervous second seed.
The 26-year-old now has the chance to add to a Maiden Tour title won in Bastad earlier in 2015.