Langer shot a closing round 67 for a 22-under total of 266 to claim the event for the fourth time. He serves as a co-promoter of the tournament. It was his 39th European Tour title in his 390th start.
Daly, who for the last month has been one of the world's hottest players, shot a 65 to share second place with Jacobson -- one shot behind Langer.
Leading by two strokes thanks to six birdies in the first 15 holes, Langer's second shot at the 17th appeared to have entered the water hazard guarding the green. Instead, the ball nestled in the wet grass short of the water and from there he chipped to eight feet and holed the crucial par putt.
Daly, winner of the BMW International Open on his last visit to Europe, gathered momentum on the back nine with an eagle at the 13th and birdies on the 15th and 16th to reach 21-under. But he was unable to come up with a birdie on the two closing holes.
Langer admitted he got lucky at the 17th.
"I played solid golf all day until the last two holes when I hit a couple of wayward shots," he said. "The 17th was a crucial hole. It was soft enough there to stop the ball and I made a good up and down for par.
"The grass was longer then in the past so I was very fortunate. Bad shots need to be penalized and we will cut it down and shave it next year."
Langer bobeyed the final hole, but was still able to celebrate with the home fans.
Daly said his second-place finish was something to relish.
"I had a slow start and a fast finish," he said. "I played the last 45 holes in 20-under par, which isn't too bad. I had a lot of opportunities and overall it's been a good week in Germany again.
"I figured I needed to shoot 8-under for the second day to get into a playoff and that's pretty much how it worked out. But I am happy to have shot a total of 48-under par for my two tournaments in Germany this year."