The German striker scored the only goal of the match at the Rhein-Neckar Arena, as the Bavarian giants ran out 1-0 winners in the Bundesliga encounter between the two teams.
"Efficient is the right word today," he told Bayern's official website after the match. "We've created chance after chance in many of our games, but not today.
"These are the games you have to win, and that's what we're doing. We didn't play well today, but sometimes you have to win without playing well. That's the decisive factor for us.
"Hoffenheim defended really aggressively. As a striker, you're waiting for the one big moment – just as I did. I'm delighted I put it away."
Bayern remain 17 points clear of Borussia Dortmund at the top of the Bundesliga table.