Gaal: Europe, you have been warned
"I am very satisfied. I think that we showed Europe tonight how strong we are, we showed that by dominating with 10 men against 11," the Dutchman said after their semi-final first leg meeting.
Bayern looked livelier than their opponents even when they were reduced to 10 men following the red card for French playmaker Ribery in the 37th minute.
"I did not think that we would win 1-0 with Ribery getting a red card," said van Gaal.
Lyon then had Jeremy Toulalan sent off for a second yellow car early in the second half to even things out.
"We dominated. I think we created more chances when we were with 10 men against 11. When we were then 10 against 10 I sent in (another striker) Mario Gomez to score a goal faster. We created many chances but scored one goal. That is good," added van Gaal.
The Bavarians won the game with Arjen Robben's 69th minute strike to take a narrow lead into the return leg next week and keep their hopes for an unprecedented treble on track.
Bayern can become the first German team to win the Champions League, the German Cup and the Bundesliga in the same season.
Lyon, in their first Champions League semi-final, looked sluggish but coach Claude Puel said the long bus ride his team endured to Munich because of the air travel chaos in Europe this week was not a factor.
"I am not looking for excuses," said Puel. "We still have some chances. We did not succeed in scoring that crucial away goal. I would have preferred to have lost with an away goal."
He said Bayern were the better team, more aggressive on the ball. "We started well but we lost the ball too easily. In the second half we were too weak with the ball.
"Ribery's red card allowed us to take control of the match but then we then we had our player sent off. Then 10 against 10 became a very difficult match for us," he said.