Djokovic had already defeated Andy Murray and Jo-Wilfried Tsonga in his previous Group A matches and the Serb knew he needed only to win one set against Berdych to be sure of qualifying.
The 25-year-old achieved that goal in just over half an hour, but he refused to take it easy after that and secured the victory which guaranteed first place in the group and potentially an easier route to the final.
In the process, Djokovic also secured his 73rd match win of 2012, moving him level with David Ferrer as the year’s two most successful players on the Tour.
Berdych’s second loss of the tournament means he is eliminated, while US Open champion Murray can seal his place in the last four by taking one set from his match against Tsonga later on Friday.
Djokovic, who has had to cope with the stress of the sudden illness that struck his father Srdjan recently, had won 10 of his previous 11 encounters with Berdych, a dominant run which included victories over the Czech in the Tour Finals for the last two years.