Czech third seed Berdych, a runner-up at Wimbledon last year, was formidable on his serve and offered up just one break point in the entire match.
Frenchman Tsonga took full advantage of that to pinch the second set, but Berdych dominated the decider to complete a 6-4 4-6 6-1 victory.
After six semi-final defeats this year, Berdych has finally won a last-four encounter and will tomorrow attempt to secure his first ATP title since triumphing in Munich in May 2009.
Standing in the way of the world number 10 will be Cilic, who beat Berdych on clay in Marseille earlier in the year.
The Croatian beat his countryman and doubles partner Ivan Ljubicic today, posting a 6-4 6-3 win several hours before Tsonga and Berdych took to the court in Beijing.
Cilic climbed as high as ninth in the world last year but currently stands at 25th, although that represents a significant recent improvement.
Like Berdych, Cilic has not won a title in 2011, but unlike his opponent tomorrow he has been to two finals, losing out in Marseille and Umag.
He also has experience of a Beijing final, having been beaten to the trophy by Novak Djokovic two years ago.