Monfils lost to Spain’s Feliciano Lopez 3-6 6-1 7-6 while Ferrer bowed out 7-5 6-4 to Stephane Robert of France.
Top-seeded Frenchman Monfils breezed through the first set in 21 minutes but was hampered by a knee injury in the second.
The final set went with serve until third seed Lopez, who sent down 11 aces in the match, raced through the tiebreak 7-1 to send the world number 13 tumbling out.
Robert made use of a devastating backhand to overcome second-seeded Spaniard Ferrer and reach his first ATP Tour final.
The 29-year-old Frenchman, ranked 100th in the world, never looked back after breaking serve in the opening game.
Ferrer saved three match points in the second set before finally succumbing to the eighth seed.
