Ballack starts as Leverkusen beat Hanover
"I am happy to have played from the start and that I have kept the trust of my coach," Ballack, who returned as a substitute last week, told reporters after the win.
The 34-year-old midfielder had been out of action since injuring his shinbone in September.
The hosts were in aggressive mood for much of the first half.
An Arturo Vidal shot sailed just wide after nine minutes but the Chilean was on target in the 21st minute, volleying in from 16 metres.
Minutes later Ballack should have done better when he was left unmarked in the box but his header from 10 metres was well off target.
Leverkusen's pressure paid off three minutes from half-time when in-form Gonzalo Castro, who scored twice last week, put Simon Rolfes through with a well-timed pass and the captain had no problems rounding keeper Ron-Robert Zieler.
"We played a clever game," said coach Jupp Heynckes. "We were compact and played with a lot of discipline."