Alaba beat Gianluigi Buffon early on with a deflected long-range strike, before Thomas Muller made it two after the break to help Bayern to a crucial win in the first leg of the Champions League quarterfinal tie.
"I wasn't expecting us to score such an early goal and I doubt Juve did either. It was a bit of a shock for them but obviously good for us," Neuer was quoted as saying on the official UEFA website. "Buffon is a superb goalkeeper and if you look at the flight of the ball, it was a really difficult one for him. I know how David shoots – they're dangerous balls to deal with.
"You can't afford to make any mistakes in the Champions League. You could see from the start that we were trying to keep hold of the ball in our build-up play, making sure every pass arrived at its destination. We didn't want to risk opening ourselves up to any counterattacks, or to allow them any chances, and I think we managed to do that very well."
The return leg in Turin takes place on April 10.