Murray, the world number three, was greeted on court at the cavernous O2 Arena like a returning hero, but the atmosphere was subdued as Berdych took the first set before the Scot turned things round to win 3-6 6-3 6-4 in the opening Group A clash.
World number one Novak Djokovic, the man Murray conquered to win his first grand slam title less than two months ago in New York, opens against Jo-Wilfried Tsonga later on Monday.
Murray's inability to convert the numerous break points he engineered almost cost him against Czech Berdych.
The Olympic champion was 15-40 ahead on Berdych's serve in the opening game and was 0-40 up in fifth game but was frustrated as Berdych produced some brutal attacking tennis to stay on terms.
The first set then swung Berdych's way with a spurt of 13 points out of 15, including a crucial service break in the sixth game when a Murray yanked a forehand low into the net.
Berdych had to save another break point as he served for the first set at 5-3 but again Murray could not convert his chance and Berdych sealed the opener when a Murray forehand flicked the net tape and sailed long.
Murray saved two break points at 1-1 in the second set and finally achieved a service break, at the 11th attempt, in the following game despite Berdych again battling back from 0-40.
That proved the turning point as Murray, with the 20,000 crowd finally coming to life, fired himself up and began to dominate the baseline exchanges.
After leveling the match he gained a decisive break of serve in the third game of the decider against a becalmed Berdych and held on for victory, only his fourth in eight matches against Berdych, sealing it when his opponent slapped a backhand into the net.
Defending champion Roger Federer begins on Tuesday against world number nine Janko Tipsarevic, who qualified for the eight-man finale in the absence of the injured Rafael Nadal. (Reporting by Martyn Herman, Editing by Tom Pilcher)