French Open champion Krejcikova needed just one hour and nine minutes to overcome Wang 6-1 6-2 and reach her third final in four tournaments.
Krejcikova controlled the match from the off, on her way to a routine win, with the world No.13 having still yet to drop a single set in the Czech capital.
Martincova had earlier been made to work a little harder for her victory over Greet Minnen, but the No.8 seed advanced through to Monday's final with a 6-3 6-4 win.
The 26-year-old let slip a 4-1 lead in the second set as Minnen pulled it back to 4-4, before taking her second match point with a strong forehand.
At the Lausanne Open, a new singles champion on the WTA Tour will be crowned on Monday when Tamara Zidansek and Clara Burel face off.
Zidansek proved too strong for semi-final debutant Maryna Zanevska, prevailing 7-5 6-3, while Burel needed to dig deep to get the better of No.5 seed Caroline Garcia.
Burel, who unlike Zidansek has never previously reached a WTA singles final at all, was a set and a break down to Garcia but recovered to take the match the distance.
The 20-year-old called a medical timeout in the decider, though she managed to put that behind her as she earned three breaks of serve to stun her French compatriot 5-7 6-2 6-2.
Elsewhere on Sunday (AEST), home favourite Dalma Galfi's tournament was brought to an end at the semi-final stage of the Hungarian Grand Prix with a 6-2 3-6 6-2 defeat to No.1 seed Yulia Putintseva.
Wildcard entrant Galfi offered little in the first set to suggest she would push Putintseva all the way, but she did exactly that with a couple of breaks of serve in the second set.
However, Putintseva, looking to add to her only previous singles title at the 2019 Nuremberg Cup, stormed into a 5-1 lead in the deciding set and ended Galfi's hopes with her first match point.
The Russian will next take on Anhelina Kalinina, who led 6-7 (7-5) 4-1 against Danielle Collins in the other semi-final when her opponent withdrew injured.