Top seed and 2012 champion Berdych saw off a determined effort from qualifier Matthias Bachinger of Germany, the Czech seed eventually prevailing 7-6 (9-7) 6-4 after a hard-fought contest.
Berdcyh's victory sees him earn another 60 ranking points in the race for the ATP World Tour Finals in London next month and boosts his hopes of appearing at the season-ending tournament at the O2 Arena.
However, he faces a tough task in order to reclaim the title against defending champion Dimitrov, who overcame Australian Bernard Tomic 6-3 7-5 to keep his title defence alive.
The Bulgarian saved two set points as he recovered from a 4-1 deficit in the second set to claim triumph and add another 60 points to his tally in the race for the Tour Finals.
Dimitrov is bullish about his prospects in the tournament showpiece at the scene of his maiden Tour win but knows that Berdych will provide stern opposition.
"I like my chances," Dimitrov said. "I never dislike my chances if I'm in the final. It's a nice place to be again.
"I would love to defend a title every single week. It brings the best out in you so for me it's a really nice place to be in.
"[Tomas is] one of the biggest hitters out there. I think we both are hungry to get that title so it’s going to be interesting."