"It was really tough but I expected it. I have played Fernando 5-6 times," said Tipsarevic, who improved to 4-2 against the Spaniard. "It's always been battles from the baseline. He made me suffer, and I ran a lot today."
He fought back from a 5-2 hole in the tiebreaker to tie it 5-all. Then the fifth-seeded Verdasco made two impatient forehand errors to lose the 52-minute opening set.
Tipsarevic saved several break points to hold for 4-4, broke to go ahead and won the quarterfinal on another forehand error by Verdasco.
Tipsarevic, chasing a spot in the eight-man ATP Finals, expects another touch match against Simon.
"I have played Gilles many times. I lost more than I won," he said. "He is the previous champion here. He knows the surface. He keeps coming back every year. I'm here for the first time. I'm expecting a tough match like today."
The fourth-seeded Simon benefited from a recurrence of Monfils' right knee injury, the same problem that kept him off the tour for four months until recently.
Simon came back from 2-0 down to win the first set, and had his own right foot re-taped to start the second. He lost the first game on serve, but quickly regained control to reach his sixth semifinals of the year.