The temperamental Russian, seeded four, took the first set with ease, breaking the 1.95 metre tall Czech in the sixth game, but lost the rain-interrupted second set before rediscovering his rhythm in a tense decider.
The final was postponed by a day following rain on Sunday.
The 23-year-old Tursunov, who recently put Russia in the Davis Cup final after beating American Andy Roddick in five sets, played some explosive forehands to quell Berdych's challenge in the first set.
But the Russian gave away easy points in the second when Berdych took control of the match after a 90-minute rain interruption.
Tursunov, who beat Spanish top seed Tommy Robredo in the semi-finals, was broken in the 10th game to lose the second set after having traded breaks and was warned by the umpire for ball abuse.
The 21-year-old Berdych, who beat the Russian at the recent U.S. Open, allowed his nerves to get the better of him and was broken in the fifth game of the decider. But he broke back in the eighth to level. They were five all when there was a second rain interruption.
The Czech was broken in a close 11th game but broke back to take the contest into the tiebreak.
Tursunov raised his game when it mattered using his hefty serve to capture the tiebreak and the contest.