The centre-half netted to cancel out Pavel Pogrebniak's opener after the Germans had dominated in the first half at the Mercedes-Benz Arena.
"You never know with Madjid," said the Rangers boss.
"I don't think there is any doubt that when he gets forward he can get forward to good purpose and that was an excellent finish.
"You don't see central defenders getting into that kind of position from open play very often. He likes to get himself forward and sometimes you don't get a great deal from him but it was nice to see him getting into that position.
"It was an excellent finish and one that any forward would have been proud of. We had a number of opportunities in the second half of the game. Steven Davis and Steven Naismith had opportunities and Sasa Papac had a header."
Rangers were a far more composed side after the interval and created their best chances in the second half but Smith denied there were any harsh words from him in the dressing room at half-time.
"I didn't think that was necessary," he said.
"Being Scottish, everybody expects you to come away and win games without any problem. We were always going to have to have a period of the game where Stuttgart were going to be in the ascendancy.
"Anyone who thinks we can come away from home and not be under any pressure are deluding themselves."
He added: "We are pleased with the result. I felt we started slowly and Stuttgart were the better side in the early part of the game."