- Donny van de Beek (49')
Van de Beek was introduced at half-time at Murrayfield and tucked away a neatly-taken volley early in the second half.
It's a welcome boost for the Netherlands midfielder, who suffered a knee injury in January which ruled him out of the second half of last season.
But speaking afterward, Van de Beek admitted he did not know whether he would remain at United for the upcoming season.
"It is hard to say where my future is," he said.
"I am coming back from injury. I have trained for a few weeks now and I have played my first minutes today.
"I am fit but I still need to keep going and try to push as hard as possible. Let's see what happens. There is also the possibility that I move -- everything is open."
Youngster Dan Gore set up Van de Beek's goal and the 18-year-old, last season's reserve team player of the season, impressed after coming on as a substitute.
Jonny Evans also came on at half-time to make his first United appearances for eight years after signing a short-term contract to cover preseason.
The 35-year-old is looking for a new club after leaving Leicester at the end of last season following their relegation from the Premier League.
Victory over Lyon was United's second summer game after beating Leeds United 2-0 in Oslo, Norway last week.
- John Beaton